diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/ArgyllRunner.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/ArgyllRunner.swift
new file mode 100644
index 0000000..3d8b82d
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/ArgyllRunner.swift
@@ -0,0 +1,207 @@
+import Foundation
+
+/// Errors from `ArgyllRunner` executions.
+public enum ArgyllRunnerError: LocalizedError, Equatable {
+    case processFailed(code: Int32, logs: [String])
+    case missingArtefact(String)
+    case malformedManifest(String)
+
+    public var errorDescription: String? {
+        switch self {
+        case .processFailed(let code, _):
+            return "Process exited with code \(code)"
+        case .missingArtefact(let path):
+            return "Expected output file was not created: \(path)"
+        case .malformedManifest(let reason):
+            return "Failed to parse printtarg manifest: \(reason)"
+        }
+    }
+}
+
+/// Result of a successful `printtarg` run: the `.ti2` artefact plus the
+/// validated manifest with per-page PNG previews already decoded.
+public struct PrinttargResult: Sendable, Equatable {
+    public let ti2URL: URL
+    public let manifest: PrinttargManifest
+    public let pages: [GalleryPage]
+}
+
+/// Service driving Argyll subprocesses off the main actor
+/// (docs/03, docs/08, docs/09).
+///
+/// - Subscribes to the event bus *before* spawning so no stdout or exit
+///   is ever lost (subscription is synchronous in `ProcessManager`).
+/// - Accumulates stdout/stderr without touching `@MainActor`; the
+///   optional `onLogBatch` callback receives coalesced chunks (20 lines
+///   or ~100 ms), never one call per line.
+/// - Exit code 0 is necessary but not sufficient: the expected artefact
+///   (`.ti1` / `.ti2`) must exist on disk, and printtarg must emit a
+///   valid `-u` manifest.
+public struct ArgyllRunner: Sendable {
+    public let processManager: ProcessManager
+    public let binaryResolver: BinaryResolver
+
+    public init(
+        processManager: ProcessManager = .shared,
+        binaryResolver: BinaryResolver = BinaryResolver()
+    ) {
+        self.processManager = processManager
+        self.binaryResolver = binaryResolver
+    }
+
+    // MARK: - targen (Stage 1)
+
+    /// Runs `targen` streaming, collecting logs and verifying `.ti1`
+    /// upon completion. Returns the `.ti1` URL.
+    public func runTargen(
+        config: TargenConfig,
+        onLogBatch: (@Sendable ([String]) -> Void)? = nil
+    ) async throws -> URL {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+        let cwd = PathSecurity.resolveSafeCwd(config.workingDirectory)
+        let args = try TargenArgs.build(config: config)
+        let binaryURL = binaryResolver.resolve("targen")
+        let processId = ProcessID.targen(cleanBasename)
+
+        let events = processManager.events()
+        try await processManager.runStreaming(
+            id: processId,
+            binary: binaryURL,
+            arguments: args,
+            workingDirectory: cwd
+        )
+        let run = await collect(id: processId, events: events, onLogBatch: onLogBatch)
+
+        guard run.exitCode == 0 else {
+            throw ArgyllRunnerError.processFailed(code: run.exitCode ?? -1, logs: run.lines)
+        }
+        let ti1URL = cwd.appendingPathComponent("\(cleanBasename).ti1")
+        guard FileManager.default.fileExists(atPath: ti1URL.path) else {
+            throw ArgyllRunnerError.missingArtefact(ti1URL.path)
+        }
+        return ti1URL
+    }
+
+    // MARK: - printtarg (Stage 2)
+
+    /// Runs `printtarg` streaming, then parses the `-u` manifest from
+    /// the complete accumulated stdout and loads each page's PNG
+    /// preview via `TiffPreview` (host-side, never raw TIFF to the UI).
+    public func runPrinttarg(
+        config: PrinttargConfig,
+        onLogBatch: (@Sendable ([String]) -> Void)? = nil
+    ) async throws -> PrinttargResult {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+        let cwd = PathSecurity.resolveSafeCwd(config.workingDirectory)
+        let args = try PrinttargArgs.build(config: config)
+        let binaryURL = binaryResolver.resolve("printtarg")
+        let processId = ProcessID.printtarg(cleanBasename)
+
+        let events = processManager.events()
+        try await processManager.runStreaming(
+            id: processId,
+            binary: binaryURL,
+            arguments: args,
+            workingDirectory: cwd
+        )
+        let run = await collect(id: processId, events: events, onLogBatch: onLogBatch)
+
+        guard run.exitCode == 0 else {
+            throw ArgyllRunnerError.processFailed(code: run.exitCode ?? -1, logs: run.lines)
+        }
+        let ti2URL = cwd.appendingPathComponent("\(cleanBasename).ti2")
+        guard FileManager.default.fileExists(atPath: ti2URL.path) else {
+            throw ArgyllRunnerError.missingArtefact(ti2URL.path)
+        }
+
+        let manifest: PrinttargManifest
+        do {
+            manifest = try PrinttargManifestExtractor.manifest(from: run.stdout)
+        } catch {
+            throw ArgyllRunnerError.malformedManifest(error.localizedDescription)
+        }
+
+        let pages = manifest.pages.enumerated().map { index, page -> GalleryPage in
+            let fileURL = cwd.appendingPathComponent(page.filename)
+            guard FileManager.default.fileExists(atPath: fileURL.path) else {
+                return GalleryPage(
+                    index: index, page: page, fileURL: fileURL,
+                    previewPNG: nil, previewError: "File not found"
+                )
+            }
+            if let png = TiffPreview.previewPNG(tiff: fileURL) {
+                return GalleryPage(
+                    index: index, page: page, fileURL: fileURL,
+                    previewPNG: png, previewError: nil
+                )
+            }
+            return GalleryPage(
+                index: index, page: page, fileURL: fileURL,
+                previewPNG: nil, previewError: "Could not decode TIFF"
+            )
+        }
+        return PrinttargResult(ti2URL: ti2URL, manifest: manifest, pages: pages)
+    }
+
+    // MARK: - Shared collection
+
+    private struct CollectedRun {
+        var exitCode: Int32?
+        var stdout: String
+        var lines: [String]
+    }
+
+    /// Drains the event stream until this child's `exit` event.
+    /// stdout is accumulated both per-line (logs) and verbatim (for
+    /// the manifest parse — the pretty JSON needs its newlines).
+    private func collect(
+        id processId: String,
+        events: AsyncStream<ProcessEvent>,
+        onLogBatch: (@Sendable ([String]) -> Void)?
+    ) async -> CollectedRun {
+        var lines: [String] = []
+        var stdout = ""
+        var pendingBatch: [String] = []
+        var exitCode: Int32?
+        var lastFlush = Date()
+
+        func flush(_ batch: inout [String]) {
+            guard !batch.isEmpty else { return }
+            let out = batch
+            batch.removeAll(keepingCapacity: true)
+            onLogBatch?(out)
+        }
+
+        for await event in events {
+            guard event.id == processId else { continue }
+            switch event {
+            case .stdout(_, let line):
+                lines.append(line)
+                stdout += line + "\n"
+                pendingBatch.append(line)
+            case .stderr(_, let line):
+                lines.append(line)
+                pendingBatch.append(line)
+            case .error(_, let message):
+                lines.append("Error: \(message)")
+                pendingBatch.append("Error: \(message)")
+            case .jsonRow:
+                // Only chartread emits these; targen/printtarg never do.
+                break
+            case .exit(_, let code):
+                exitCode = code
+            }
+            if exitCode == nil,
+               pendingBatch.count >= 20
+                || Date().timeIntervalSince(lastFlush) >= 0.1 {
+                flush(&pendingBatch)
+                lastFlush = Date()
+            }
+            if exitCode != nil {
+                flush(&pendingBatch)
+                break
+            }
+        }
+        return CollectedRun(exitCode: exitCode, stdout: stdout, lines: lines)
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargArgs.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargArgs.swift
new file mode 100644
index 0000000..bd4280c
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargArgs.swift
@@ -0,0 +1,99 @@
+import Foundation
+
+/// Errors during `buildPrinttargArgs` validation (docs/04 §2.2).
+public enum PrinttargArgError: LocalizedError, Equatable {
+    case invalidCustomPageDimension(Double)
+    case invalidDPI(Int)
+    case invalidSeed(Int)
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidCustomPageDimension(let mm):
+            return "Custom page dimensions must be at least 50 mm, got: \(mm)"
+        case .invalidDPI(let dpi):
+            return "TIFF DPI must be between 72 and 600, got: \(dpi)"
+        case .invalidSeed(let seed):
+            return "Custom layout seed must be ≥ 1, got: \(seed)"
+        }
+    }
+}
+
+/// Pure argv builder for Argyll's `printtarg` tool (docs/09, docs/04 §2.2).
+///
+/// Contract:
+/// ```
+/// -v -u -i {instrument} -p {page} [-r | -R seed] [-d label] {-t|-T} {dpi} [-K|-I cal] basename
+/// ```
+public enum PrinttargArgs {
+
+    /// Builds the exact command-line arguments for `printtarg`.
+    ///
+    /// Invariants:
+    /// - Always `-v -u` (the fork's `-u` emits the JSON page manifest).
+    /// - Default layout is deterministic `-R 1` (#163) — a missing seed
+    ///   reshuffles patches on every re-run and desyncs print vs `.ti2`.
+    /// - `.raster` emits `-r` and supersedes any seed. This is NOT
+    ///   targen's `-r` full-spread algorithm (docs/25).
+    /// - `-d` is the chart **label** string, not colour space.
+    /// - `-K`/`-I` are never emitted for `CAL_` basenames — the
+    ///   calibration chart must not embed its own curves.
+    /// - Basename is the last positional argument.
+    public static func build(config: PrinttargConfig) throws -> [String] {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+
+        var args: [String] = [
+            "-v", "-u",
+            "-i", config.instrument.rawValue,
+            "-p", try pageSizeValue(config),
+        ]
+
+        switch config.layoutOrder {
+        case .deterministic:
+            args.append(contentsOf: ["-R", "1"])
+        case .customSeed:
+            guard config.customSeed >= 1 else {
+                throw PrinttargArgError.invalidSeed(config.customSeed)
+            }
+            args.append(contentsOf: ["-R", "\(config.customSeed)"])
+        case .raster:
+            args.append("-r")
+        }
+
+        if let label = config.label?.trimmingCharacters(in: .whitespacesAndNewlines),
+           !label.isEmpty {
+            args.append(contentsOf: ["-d", label])
+        }
+
+        guard (72...600).contains(config.dpi) else {
+            throw PrinttargArgError.invalidDPI(config.dpi)
+        }
+        args.append(contentsOf: [config.bitDepth.flag, "\(config.dpi)"])
+
+        if !cleanBasename.hasPrefix("CAL_"),
+           let cal = config.calibrationFile?.trimmingCharacters(in: .whitespacesAndNewlines),
+           !cal.isEmpty {
+            args.append(contentsOf: [config.calibrationEmbedOnly ? "-I" : "-K", cal])
+        }
+
+        args.append(cleanBasename)
+        return args
+    }
+
+    private static func pageSizeValue(_ config: PrinttargConfig) throws -> String {
+        guard config.pageSize == .custom else { return config.pageSize.rawValue }
+        for dim in [config.customPageWidth, config.customPageHeight] {
+            guard dim >= 50 else {
+                throw PrinttargArgError.invalidCustomPageDimension(dim)
+            }
+        }
+        return "\(formatMM(config.customPageWidth))x\(formatMM(config.customPageHeight))"
+    }
+
+    /// Formats millimetres as an integer when exact, else decimal.
+    private static func formatMM(_ value: Double) -> String {
+        if value == value.rounded(), abs(value) < 1e15 {
+            return "\(Int(value))"
+        }
+        return String(format: "%.1f", locale: Locale(identifier: "en_US_POSIX"), value)
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargConfig.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargConfig.swift
new file mode 100644
index 0000000..6e93351
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargConfig.swift
@@ -0,0 +1,208 @@
+import Foundation
+
+/// Measurement instrument for `printtarg -i` chart geometry
+/// (docs/09, docs/04 §2.2). Raw values are the Argyll codes.
+public enum PrintInstrument: String, Codable, Sendable, CaseIterable {
+    case i1
+    case p3
+    case cm = "CM"
+    case ss = "SS"
+    case dtp20 = "20"
+    case dtp22 = "22"
+    case dtp41 = "41"
+    case dtp51 = "51"
+
+    public var displayName: String {
+        switch self {
+        case .i1:    return "X-Rite i1Pro / i1Pro 2"
+        case .p3:    return "X-Rite i1Pro 3 / 3 Plus"
+        case .cm:    return "ColorMunki"
+        case .ss:    return "Specbos / Spectraval (XY table)"
+        case .dtp20: return "Gretag i1Display 2"
+        case .dtp22: return "X-Rite i1Display Pro / ColorMunki Display"
+        case .dtp41: return "Datacolor Spyder 4/5"
+        case .dtp51: return "Spyder X"
+        }
+    }
+}
+
+/// Page size for `printtarg -p` (docs/09). `.custom` emits `{W}x{H}` mm.
+public enum PageSize: String, Codable, Sendable, CaseIterable {
+    case a4 = "A4"
+    case a4r = "A4R"
+    case a3 = "A3"
+    case a2 = "A2"
+    case letter = "Letter"
+    case letterR = "LetterR"
+    case legal = "Legal"
+    case fourBySix = "4x6"
+    case elevenBySeventeen = "11x17"
+    case custom = "custom"
+
+    public var isCustom: Bool { self == .custom }
+}
+
+/// TIFF bit depth: `-t` (8-bit) or `-T` (16-bit).
+public enum TiffBitDepth: Int, Codable, Sendable, CaseIterable {
+    case eight = 8
+    case sixteen = 16
+
+    public var flag: String {
+        switch self {
+        case .eight:   return "-t"
+        case .sixteen: return "-T"
+        }
+    }
+}
+
+/// Patch layout order (docs/09 §Randomisation, #163).
+/// `.deterministic` is the default (`-R 1`); `.raster` emits `-r` and
+/// supersedes any seed — never confuse with targen's `-r` algorithm.
+public enum LayoutOrder: String, Codable, Sendable, CaseIterable {
+    case deterministic
+    case customSeed = "custom_seed"
+    case raster
+
+    public var displayName: String {
+        switch self {
+        case .deterministic: return "Deterministic (seed 1)"
+        case .customSeed:    return "Custom seed"
+        case .raster:        return "Raster order (no shuffle)"
+        }
+    }
+}
+
+/// Chart label metadata used to assemble the automatic `printtarg -d`
+/// label. Any empty/missing component becomes `Unspecified` until real
+/// printer metadata lands in M3.
+public struct TargetLabelMetadata: Codable, Equatable, Sendable {
+    public var printer: String
+    public var inkSet: String
+    public var driverPaper: String
+    public var actualPaper: String
+
+    public init(
+        printer: String = "",
+        inkSet: String = "",
+        driverPaper: String = "",
+        actualPaper: String = ""
+    ) {
+        self.printer = printer
+        self.inkSet = inkSet
+        self.driverPaper = driverPaper
+        self.actualPaper = actualPaper
+    }
+}
+
+/// Builds the chart legend for `printtarg -d` (fork argyllcms#19,
+/// ICCery #119). `-d` here is a **label string** — not targen's colour
+/// space, not iccgamut's density (docs/25).
+public enum PrinttargLabel {
+
+    public static let unspecified = "Unspecified"
+
+    /// `ICCery - {basename} - {printer} - {ink} - {driverPaper} -
+    /// {actualPaper} - DD/MM/YYYY HH:MM`
+    ///
+    /// `date` is injected for deterministic tests; production passes
+    /// the current local time. A fixed POSIX locale keeps the format
+    /// stable regardless of user locale.
+    public static func automatic(
+        basename: String,
+        metadata: TargetLabelMetadata,
+        date: Date = Date(),
+        timeZone: TimeZone = .current
+    ) -> String {
+        let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.timeZone = timeZone
+        formatter.dateFormat = "dd/MM/yyyy HH:mm"
+
+        return [
+            "ICCery",
+            basename,
+            field(metadata.printer),
+            field(metadata.inkSet),
+            field(metadata.driverPaper),
+            field(metadata.actualPaper),
+            formatter.string(from: date),
+        ].joined(separator: " - ")
+    }
+
+    /// Resolves the label to emit: an explicit non-empty manual label
+    /// wins; otherwise the assembled automatic label.
+    public static func resolved(
+        customLabel: String?,
+        basename: String,
+        metadata: TargetLabelMetadata,
+        date: Date = Date(),
+        timeZone: TimeZone = .current
+    ) -> String {
+        if let label = customLabel?.trimmingCharacters(in: .whitespacesAndNewlines),
+           !label.isEmpty {
+            return label
+        }
+        return automatic(basename: basename, metadata: metadata, date: date, timeZone: timeZone)
+    }
+
+    private static func field(_ value: String) -> String {
+        let trimmed = value.trimmingCharacters(in: .whitespacesAndNewlines)
+        return trimmed.isEmpty ? unspecified : trimmed
+    }
+}
+
+/// Configuration model for `printtarg` invocation (docs/09, docs/04 §2.2).
+public struct PrinttargConfig: Codable, Equatable, Sendable {
+    public var instrument: PrintInstrument
+    public var pageSize: PageSize
+    /// Custom page dimensions in millimetres; each must be ≥ 50 when
+    /// `pageSize == .custom`.
+    public var customPageWidth: Double
+    public var customPageHeight: Double
+    public var bitDepth: TiffBitDepth
+    public var dpi: Int
+    public var layoutOrder: LayoutOrder
+    /// Seed for `.customSeed` layout (`-R N`, N ≥ 1). Ignored for
+    /// `.deterministic` (fixed `-R 1`) and `.raster` (`-r`).
+    public var customSeed: Int
+    /// Resolved `-d` label. Callers usually compute this via
+    /// `PrinttargLabel.resolved` so tests can inject the clock.
+    public var label: String?
+    /// `.cal` file applied to printed patches (`-K`), or embedded
+    /// without applying (`-I` when `calibrationEmbedOnly`). Never
+    /// emitted for `CAL_` basenames (Stage 0 protection).
+    public var calibrationFile: String?
+    public var calibrationEmbedOnly: Bool
+    public var basename: String
+    public var workingDirectory: URL?
+
+    public init(
+        instrument: PrintInstrument = .i1,
+        pageSize: PageSize = .a4,
+        customPageWidth: Double = 210,
+        customPageHeight: Double = 297,
+        bitDepth: TiffBitDepth = .eight,
+        dpi: Int = 300,
+        layoutOrder: LayoutOrder = .deterministic,
+        customSeed: Int = 1,
+        label: String? = nil,
+        calibrationFile: String? = nil,
+        calibrationEmbedOnly: Bool = false,
+        basename: String = "",
+        workingDirectory: URL? = nil
+    ) {
+        self.instrument = instrument
+        self.pageSize = pageSize
+        self.customPageWidth = customPageWidth
+        self.customPageHeight = customPageHeight
+        self.bitDepth = bitDepth
+        self.dpi = dpi
+        self.layoutOrder = layoutOrder
+        self.customSeed = customSeed
+        self.label = label
+        self.calibrationFile = calibrationFile
+        self.calibrationEmbedOnly = calibrationEmbedOnly
+        self.basename = basename
+        self.workingDirectory = workingDirectory
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargManifest.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargManifest.swift
new file mode 100644
index 0000000..b5c9e70
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/PrinttargManifest.swift
@@ -0,0 +1,180 @@
+import Foundation
+
+/// One page of a `printtarg -u` manifest (docs/05 §2.3).
+/// `patches` is a page-assigned count including TID/padding cells,
+/// not strictly user patches.
+public struct PrinttargPage: Codable, Equatable, Sendable {
+    public var filename: String
+    public var patches: Int
+    public var widthMm: Double
+    public var heightMm: Double
+
+    public init(filename: String, patches: Int, widthMm: Double, heightMm: Double) {
+        self.filename = filename
+        self.patches = patches
+        self.widthMm = widthMm
+        self.heightMm = heightMm
+    }
+
+    enum CodingKeys: String, CodingKey {
+        case filename, patches
+        case widthMm = "width_mm"
+        case heightMm = "height_mm"
+    }
+}
+
+/// The final-only, pretty-printed, **unprefixed** JSON object emitted
+/// by fork `printtarg -u` after all pages are written (docs/05 §2.3).
+public struct PrinttargManifest: Codable, Equatable, Sendable {
+    public var event: String
+    public var pages: [PrinttargPage]
+
+    public init(event: String = "manifest", pages: [PrinttargPage]) {
+        self.event = event
+        self.pages = pages
+    }
+}
+
+/// A manifest page resolved against the working directory, with its
+/// host-side PNG preview (#58 — TIFF is never fed to the UI directly).
+public struct GalleryPage: Equatable, Sendable, Identifiable {
+    public var id: Int { index }
+    public let index: Int
+    public let page: PrinttargPage
+    public let fileURL: URL
+    public let previewPNG: Data?
+    public let previewError: String?
+
+    public init(index: Int, page: PrinttargPage, fileURL: URL, previewPNG: Data?, previewError: String?) {
+        self.index = index
+        self.page = page
+        self.fileURL = fileURL
+        self.previewPNG = previewPNG
+        self.previewError = previewError
+    }
+}
+
+public enum ManifestError: LocalizedError, Equatable {
+    case noJSONDocument
+    case wrongEvent(String)
+    case decodeFailed(String)
+    case invalidPage(String)
+
+    public var errorDescription: String? {
+        switch self {
+        case .noJSONDocument:
+            return "No JSON document found in printtarg stdout."
+        case .wrongEvent(let event):
+            return "Unexpected JSON event \"\(event)\" — expected \"manifest\"."
+        case .decodeFailed(let reason):
+            return "printtarg manifest JSON failed to decode: \(reason)"
+        case .invalidPage(let reason):
+            return "printtarg manifest page is invalid: \(reason)"
+        }
+    }
+}
+
+/// Extracts and decodes the `printtarg -u` manifest from the complete
+/// accumulated stdout (docs/04 §2.3, docs/09 §JSON manifest).
+///
+/// #68 invariant: the JSON is a structured document, not a brace-hunt.
+/// Extraction is string/escape-aware — a `{` or `}` inside a quoted
+/// filename can never corrupt the scan — and starts only at a `{` that
+/// begins a trimmed stdout line.
+public enum PrinttargManifestExtractor {
+
+    /// Finds the manifest object in accumulated stdout.
+    public static func manifest(from stdout: String) throws -> PrinttargManifest {
+        for block in jsonObjects(in: stdout) {
+            let data = Data(block.utf8)
+            guard let manifest = try? JSONDecoder().decode(PrinttargManifest.self, from: data) else {
+                continue
+            }
+            guard manifest.event == "manifest" else {
+                throw ManifestError.wrongEvent(manifest.event)
+            }
+            try validate(manifest)
+            return manifest
+        }
+        if let first = jsonObjects(in: stdout).first,
+           let obj = try? JSONSerialization.jsonObject(with: Data(first.utf8)) as? [String: Any],
+           let event = obj["event"] as? String {
+            throw ManifestError.wrongEvent(event)
+        }
+        throw ManifestError.noJSONDocument
+    }
+
+    private static func validate(_ manifest: PrinttargManifest) throws {
+        for page in manifest.pages {
+            guard page.patches >= 0 else {
+                throw ManifestError.invalidPage("negative patch count \(page.patches)")
+            }
+            guard page.widthMm > 0, page.heightMm > 0 else {
+                throw ManifestError.invalidPage("non-positive page size \(page.widthMm)x\(page.heightMm)")
+            }
+            let name = page.filename
+            guard !name.isEmpty,
+                  !name.hasPrefix("/"),
+                  !name.contains("/"),
+                  !name.contains("\\"),
+                  !name.contains("..") else {
+                throw ManifestError.invalidPage("unsafe filename \"\(name)\"")
+            }
+            let ext = (name as NSString).pathExtension.lowercased()
+            guard ext == "tif" || ext == "tiff" else {
+                throw ManifestError.invalidPage("non-TIFF filename \"\(name)\"")
+            }
+        }
+    }
+
+    /// Yields every complete top-level JSON object `{...}` found at a
+    /// trimmed line boundary, in document order. Depth tracking respects
+    /// quoted strings and backslash escapes.
+    static func jsonObjects(in text: String) -> [String] {
+        var out: [String] = []
+        let scalars = Array(text.unicodeScalars)
+        var i = 0
+
+        func isLineStart(_ idx: Int) -> Bool {
+            var j = idx - 1
+            while j >= 0 && scalars[j] != "\n" {
+                if scalars[j] != " " && scalars[j] != "\t" && scalars[j] != "\r" {
+                    return false
+                }
+                j -= 1
+            }
+            return true
+        }
+
+        while i < scalars.count {
+            if scalars[i] == "{", isLineStart(i) {
+                var depth = 0
+                var inString = false
+                var escaped = false
+                var j = i
+                while j < scalars.count {
+                    let c = scalars[j]
+                    if inString {
+                        if escaped { escaped = false }
+                        else if c == "\\" { escaped = true }
+                        else if c == "\"" { inString = false }
+                    } else {
+                        if c == "\"" { inString = true }
+                        else if c == "{" { depth += 1 }
+                        else if c == "}" {
+                            depth -= 1
+                            if depth == 0 {
+                                out.append(String(String.UnicodeScalarView(scalars[i...j])))
+                                i = j
+                                break
+                            }
+                        }
+                    }
+                    j += 1
+                }
+            }
+            i += 1
+        }
+        return out
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/TargenArgs.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/TargenArgs.swift
new file mode 100644
index 0000000..b9c14b8
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/TargenArgs.swift
@@ -0,0 +1,104 @@
+import Foundation
+
+/// Errors during `buildTargenArgs` validation (docs/04 §1.2).
+public enum TargenArgError: LocalizedError, Equatable {
+    case invalidBasename(String)
+    case invalidPatchCount(Int)
+    case invalidWhitePatches(Int)
+    case invalidBlackPatches(Int)
+    case invalidInkLimit(Int)
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidBasename(let name):
+            return "Invalid target basename: \(name)"
+        case .invalidPatchCount(let count):
+            return "Patch count must be positive, got: \(count)"
+        case .invalidWhitePatches(let count):
+            return "White patches cannot be negative, got: \(count)"
+        case .invalidBlackPatches(let count):
+            return "Black patches cannot be negative, got: \(count)"
+        case .invalidInkLimit(let limit):
+            return "Ink limit must be between 1 and 400, got: \(limit)"
+        }
+    }
+}
+
+/// Pure argv builder for Argyll's `targen` tool (docs/08, docs/04 §1.2).
+public enum TargenArgs {
+
+    /// Builds the exact command-line arguments for `targen`.
+    ///
+    /// Invariants:
+    /// - Always starts `-v -d {2|4}` (RGB=2, CMYK=4).
+    /// - Never emits `-u` (Argyll fork progress is not enabled for targen).
+    /// - Always emits `-f N` when patchCount > 0 (#44).
+    /// - White `-e`, Black `-B`.
+    /// - `-N` omitted when approximately 0.50.
+    /// - `-A` is emitted even at 0.10 (no default-skip).
+    /// - `-l` is CMYK only (1...400).
+    /// - `-V` omitted when approximately 1.0.
+    /// - `-p` omitted when non-positive or approximately 1.0.
+    /// - Basename is the last positional argument.
+    public static func build(config: TargenConfig) throws -> [String] {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+
+        guard config.patchCount > 0 else {
+            throw TargenArgError.invalidPatchCount(config.patchCount)
+        }
+        guard config.whitePatches >= 0 else {
+            throw TargenArgError.invalidWhitePatches(config.whitePatches)
+        }
+        guard config.blackPatches >= 0 else {
+            throw TargenArgError.invalidBlackPatches(config.blackPatches)
+        }
+
+        var args: [String] = [
+            "-v",
+            "-d", config.colourSpace.dFlagValue,
+            "-f", "\(config.patchCount)",
+            "-e", "\(config.whitePatches)",
+            "-B", "\(config.blackPatches)"
+        ]
+
+        if let g = config.greySteps, g > 0 {
+            args.append(contentsOf: ["-g", "\(g)"])
+        }
+        if let s = config.singleChannelSteps, s > 0 {
+            args.append(contentsOf: ["-s", "\(s)"])
+        }
+        if let n = config.neutralSteps, n > 0 {
+            args.append(contentsOf: ["-n", "\(n)"])
+        }
+        if let nConc = config.neutralConcentration, abs(nConc - 0.50) >= 0.001 {
+            args.append(contentsOf: ["-N", String(format: "%.2f", locale: Locale(identifier: "en_US_POSIX"), nConc)])
+        }
+        if let c = config.preconditioningProfile?.trimmingCharacters(in: .whitespacesAndNewlines), !c.isEmpty {
+            args.append(contentsOf: ["-c", c])
+        }
+        if config.ofpsHighQuality == true {
+            args.append("-G")
+        }
+        if let a = config.ofpsAdaptation {
+            args.append(contentsOf: ["-A", String(format: "%.2f", locale: Locale(identifier: "en_US_POSIX"), a)])
+        }
+        if let algFlag = config.fullSpreadAlgorithm?.flag {
+            args.append(algFlag)
+        }
+        if config.colourSpace == .cmyk, let inkLimit = config.totalInkLimit {
+            guard (1...400).contains(inkLimit) else {
+                throw TargenArgError.invalidInkLimit(inkLimit)
+            }
+            args.append(contentsOf: ["-l", "\(inkLimit)"])
+        }
+        if let v = config.darkEmphasis, abs(v - 1.0) >= 0.001 {
+            args.append(contentsOf: ["-V", String(format: "%.2f", locale: Locale(identifier: "en_US_POSIX"), v)])
+        }
+        if let p = config.devicePower, p > 0, abs(p - 1.0) >= 0.001 {
+            args.append(contentsOf: ["-p", String(format: "%.2f", locale: Locale(identifier: "en_US_POSIX"), p)])
+        }
+
+        args.append(cleanBasename)
+        return args
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/TargenConfig.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/TargenConfig.swift
new file mode 100644
index 0000000..fa62fdd
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Argyll/TargenConfig.swift
@@ -0,0 +1,150 @@
+import Foundation
+
+/// Colour space for patch generation (docs/08, docs/04 §1.2).
+public enum ColourSpace: String, Codable, Sendable, CaseIterable {
+    case rgb
+    case cmyk
+
+    /// Argyll targen `-d` flag argument: 2 for RGB, 4 for CMYK.
+    public var dFlagValue: String {
+        switch self {
+        case .rgb: return "2"
+        case .cmyk: return "4"
+        }
+    }
+}
+
+/// Patch count preset for Stage 1.
+public enum PatchCountPreset: String, Codable, Sendable, CaseIterable {
+    case draft400 = "400"
+    case standard800 = "800"
+    case photo1500 = "1500"
+    case custom = "custom"
+
+    public var patchCount: Int? {
+        switch self {
+        case .draft400: return 400
+        case .standard800: return 800
+        case .photo1500: return 1500
+        case .custom: return nil
+        }
+    }
+
+    public var title: String {
+        switch self {
+        case .draft400: return "Draft (400)"
+        case .standard800: return "Standard (800)"
+        case .photo1500: return "Photo (1500)"
+        case .custom: return "Custom"
+        }
+    }
+}
+
+/// Full spread patch distribution algorithm (docs/08).
+/// Default is "ofps" (no flag emitted).
+public enum FullSpreadAlgorithm: String, Codable, Sendable, CaseIterable {
+    case ofps = "ofps"
+    case target = "-t"
+    case random = "-r"
+    case uniformRandom = "-R"
+    case quasiRandom = "-q"
+    case uniformQuasiRandom = "-Q"
+    case invertedQuasiRandom = "-i"
+    case invertedUniformQuasiRandom = "-I"
+
+    public var displayName: String {
+        switch self {
+        case .ofps: return "OFPS (Default)"
+        case .target: return "Target (-t)"
+        case .random: return "Random (-r)"
+        case .uniformRandom: return "Uniform Random (-R)"
+        case .quasiRandom: return "Quasi-random (-q)"
+        case .uniformQuasiRandom: return "Uniform Quasi-random (-Q)"
+        case .invertedQuasiRandom: return "Inverted Quasi-random (-i)"
+        case .invertedUniformQuasiRandom: return "Inverted Uniform Quasi-random (-I)"
+        }
+    }
+
+    public var flag: String? {
+        switch self {
+        case .ofps: return nil
+        default: return rawValue
+        }
+    }
+
+    /// Preset JSON value: `"ofps"` or the bare flag letter
+    /// (`t`, `r`, `R`, `q`, `Q`, `i`, `I`) — docs/22.
+    public var presetValue: String {
+        switch self {
+        case .ofps: return "ofps"
+        default: return String(rawValue.dropFirst())
+        }
+    }
+
+    public init?(presetValue: String) {
+        if presetValue == "ofps" {
+            self = .ofps
+        } else {
+            self.init(rawValue: "-" + presetValue)
+        }
+    }
+}
+
+/// Configuration model for `targen` invocation (docs/08, docs/04 §1.2).
+public struct TargenConfig: Codable, Equatable, Sendable {
+    public var colourSpace: ColourSpace
+    public var patchCount: Int
+    public var whitePatches: Int
+    public var blackPatches: Int
+    public var greySteps: Int?
+    public var singleChannelSteps: Int?
+    public var neutralSteps: Int?
+    public var neutralConcentration: Double?
+    public var preconditioningProfile: String?
+    public var ofpsHighQuality: Bool?
+    public var ofpsAdaptation: Double?
+    public var fullSpreadAlgorithm: FullSpreadAlgorithm?
+    public var totalInkLimit: Int?
+    public var darkEmphasis: Double?
+    public var devicePower: Double?
+    public var basename: String
+    public var workingDirectory: URL?
+
+    public init(
+        colourSpace: ColourSpace = .rgb,
+        patchCount: Int = 800,
+        whitePatches: Int = 4,
+        blackPatches: Int = 4,
+        greySteps: Int? = nil,
+        singleChannelSteps: Int? = nil,
+        neutralSteps: Int? = nil,
+        neutralConcentration: Double? = nil,
+        preconditioningProfile: String? = nil,
+        ofpsHighQuality: Bool? = nil,
+        ofpsAdaptation: Double? = nil,
+        fullSpreadAlgorithm: FullSpreadAlgorithm? = nil,
+        totalInkLimit: Int? = nil,
+        darkEmphasis: Double? = nil,
+        devicePower: Double? = nil,
+        basename: String = "",
+        workingDirectory: URL? = nil
+    ) {
+        self.colourSpace = colourSpace
+        self.patchCount = patchCount
+        self.whitePatches = whitePatches
+        self.blackPatches = blackPatches
+        self.greySteps = greySteps
+        self.singleChannelSteps = singleChannelSteps
+        self.neutralSteps = neutralSteps
+        self.neutralConcentration = neutralConcentration
+        self.preconditioningProfile = preconditioningProfile
+        self.ofpsHighQuality = ofpsHighQuality
+        self.ofpsAdaptation = ofpsAdaptation
+        self.fullSpreadAlgorithm = fullSpreadAlgorithm
+        self.totalInkLimit = totalInkLimit
+        self.darkEmphasis = darkEmphasis
+        self.devicePower = devicePower
+        self.basename = basename
+        self.workingDirectory = workingDirectory
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Paths/AppPaths.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Paths/AppPaths.swift
index 24a280f..3cda13c 100644
--- a/Packages/ICCeryCore/Sources/ICCeryCore/Paths/AppPaths.swift
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Paths/AppPaths.swift
@@ -14,20 +14,41 @@ public enum AppPaths {
     }
 
     /// `~/Library/Application Support/com.gronod.iccery2`
+    ///
+    /// DEBUG only: `ICCERY_TEST_ROOT` redirects app data so UI tests run
+    /// against an isolated root and never touch the developer's state.
     public static var appDataDir: URL {
-        FileManager.default
+        #if DEBUG
+        if let root = testRoot {
+            return root.appendingPathComponent("AppData", isDirectory: true)
+        }
+        #endif
+        return FileManager.default
             .urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
             .appendingPathComponent(bundleIdentifier, isDirectory: true)
     }
 
     /// `~/Library/Logs/com.gronod.iccery2`
     public static var logDir: URL {
-        FileManager.default
+        #if DEBUG
+        if let root = testRoot {
+            return root.appendingPathComponent("Logs", isDirectory: true)
+        }
+        #endif
+        return FileManager.default
             .urls(for: .libraryDirectory, in: .userDomainMask)[0]
             .appendingPathComponent("Logs", isDirectory: true)
             .appendingPathComponent(bundleIdentifier, isDirectory: true)
     }
 
+    #if DEBUG
+    private static var testRoot: URL? {
+        guard let raw = ProcessInfo.processInfo.environment["ICCERY_TEST_ROOT"],
+              !raw.isEmpty else { return nil }
+        return URL(fileURLWithPath: raw, isDirectory: true)
+    }
+    #endif
+
     /// `~/Library/Logs/com.gronod.iccery2/iccery.log`
     public static var logFile: URL {
         logDir.appendingPathComponent("iccery.log", isDirectory: false)
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessEvent.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessEvent.swift
index d04acf3..ea5b54b 100644
--- a/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessEvent.swift
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessEvent.swift
@@ -34,3 +34,18 @@ public enum ProcessError: Error, Equatable, Sendable {
     /// stdin write failed (pipe closed / process gone).
     case stdinFailed(String)
 }
+
+extension ProcessError: LocalizedError {
+    public var errorDescription: String? {
+        switch self {
+        case .duplicateID(let id):
+            return "Process already running: \(id)"
+        case .unknownID(let id):
+            return "Unknown process: \(id)"
+        case .spawnFailed(let detail):
+            return "Could not launch \(detail)"
+        case .stdinFailed(let detail):
+            return "stdin failed: \(detail)"
+        }
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessManager.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessManager.swift
index 1e130af..6bfe6ab 100644
--- a/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessManager.swift
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessManager.swift
@@ -30,37 +30,54 @@ public actor ProcessManager {
 
     // MARK: - Event bus (multicast)
 
-    private var subscribers: [UUID: AsyncStream<ProcessEvent>.Continuation] = [:]
+    /// Lock-protected subscriber table. Registration is *synchronous*
+    /// inside `events()` so a caller can subscribe, then spawn, without
+    /// racing the child's first output or exit event.
+    private final class SubscriberBox: @unchecked Sendable {
+        private let lock = NSLock()
+        private var map: [UUID: AsyncStream<ProcessEvent>.Continuation] = [:]
 
-    /// Subscribe to the event bus. Each call returns an independent
-    /// stream; every event is delivered to every live subscriber.
-    public nonisolated func events() -> AsyncStream<ProcessEvent> {
-        AsyncStream { continuation in
-            let token = UUID()
-            Task { await self.addSubscriber(continuation, token: token) }
-            continuation.onTermination = { _ in
-                Task { await self.removeSubscriber(token) }
+        func add(_ continuation: AsyncStream<ProcessEvent>.Continuation, token: UUID) {
+            lock.lock()
+            map[token] = continuation
+            lock.unlock()
+        }
+
+        func remove(_ token: UUID) {
+            lock.lock()
+            map.removeValue(forKey: token)
+            lock.unlock()
+        }
+
+        func yield(_ event: ProcessEvent) {
+            lock.lock()
+            let continuations = Array(map.values)
+            lock.unlock()
+            for continuation in continuations {
+                continuation.yield(event)
             }
         }
     }
 
-    private func addSubscriber(
-        _ continuation: AsyncStream<ProcessEvent>.Continuation,
-        token: UUID
-    ) {
-        subscribers[token] = continuation
-    }
+    private nonisolated let subscriberBox = SubscriberBox()
 
-    private func removeSubscriber(_ token: UUID) {
-        subscribers.removeValue(forKey: token)
-    }
-
-    private func emit(_ event: ProcessEvent) {
-        for continuation in subscribers.values {
-            continuation.yield(event)
+    /// Subscribe to the event bus. Each call returns an independent
+    /// stream; every event is delivered to every live subscriber.
+    /// The subscriber is registered before `events()` returns — callers
+    /// may spawn immediately after subscribing without losing events.
+    public nonisolated func events() -> AsyncStream<ProcessEvent> {
+        let box = subscriberBox
+        let token = UUID()
+        return AsyncStream { continuation in
+            box.add(continuation, token: token)
+            continuation.onTermination = { _ in box.remove(token) }
         }
     }
 
+    private nonisolated func emit(_ event: ProcessEvent) {
+        subscriberBox.yield(event)
+    }
+
     // MARK: - Child registry
 
     private struct RunningChild {
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Settings/AppSettings.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/AppSettings.swift
index 2464ac9..6e81bf9 100644
--- a/Packages/ICCeryCore/Sources/ICCeryCore/Settings/AppSettings.swift
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/AppSettings.swift
@@ -1,7 +1,8 @@
 import Foundation
 
-/// A saved wizard preset slot (docs/22 §Presets). The preset *engine*
-/// lands in issue #11; for M1 the store only needs a Codable container.
+/// Legacy M1 preset shape (`name` + opaque string dictionary). Retained
+/// solely to decode and migrate pre-M2 `settings.json`; new code uses
+/// `ProfilingPreset` (docs/22 §ProfilingPreset).
 public struct CustomPreset: Codable, Equatable, Sendable {
     public var name: String
     /// Opaque per-stage form values — keyed by field id.
@@ -21,6 +22,11 @@ public enum InstallLocation: String, Codable, Sendable, CaseIterable {
 
 /// `settings.json` model (docs/22). snake_case keys match the v1 file
 /// so field names stay identical across rewrites.
+///
+/// Decoding is tolerant: missing keys take documented defaults and each
+/// `custom_presets` element is tried as a typed `ProfilingPreset` first
+/// and as a legacy M1 `CustomPreset` second — a malformed entry never
+/// drops the rest of the array (preset migration, issue #11).
 public struct AppSettings: Codable, Equatable, Sendable {
 
     /// User override for Argyll binaries; `nil` → bundled sidecars.
@@ -35,7 +41,7 @@ public struct AppSettings: Codable, Equatable, Sendable {
 
     public var deltaEGoodMax: Double
     public var deltaEWarningMax: Double
-    public var customPresets: [CustomPreset]
+    public var customPresets: [ProfilingPreset]
     public var enableI1Pro2Leds: Bool
     public var calibrationStaleDays: Int
     public var defaultInstallLocation: InstallLocation
@@ -48,7 +54,7 @@ public struct AppSettings: Codable, Equatable, Sendable {
         logLevel: LogLevel? = nil,
         deltaEGoodMax: Double = 2.0,
         deltaEWarningMax: Double = 5.0,
-        customPresets: [CustomPreset] = [],
+        customPresets: [ProfilingPreset] = [],
         enableI1Pro2Leds: Bool = false,
         calibrationStaleDays: Int = 30,
         defaultInstallLocation: InstallLocation = .user,
@@ -94,6 +100,62 @@ public struct AppSettings: Codable, Equatable, Sendable {
         case openColorPanelAfterInstall = "open_color_panel_after_install"
     }
 
+    /// One element of `custom_presets`: typed first, legacy M1 second.
+    private enum AnyPreset: Decodable {
+        case typed(ProfilingPreset)
+        case legacy(CustomPreset)
+
+        init(from decoder: Decoder) throws {
+            if let p = try? ProfilingPreset(from: decoder) {
+                self = .typed(p)
+                return
+            }
+            self = .legacy(try CustomPreset(from: decoder))
+        }
+    }
+
+    public init(from decoder: Decoder) throws {
+        let c = try decoder.container(keyedBy: CodingKeys.self)
+        let d = AppSettings.default
+        argyllBinaryDir = try c.decodeIfPresent(String.self, forKey: .argyllBinaryDir) ?? d.argyllBinaryDir
+        defaultInstrument = try c.decodeIfPresent(String.self, forKey: .defaultInstrument) ?? d.defaultInstrument
+        logLevel = try c.decodeIfPresent(LogLevel.self, forKey: .logLevel) ?? d.logLevel
+        deltaEGoodMax = try c.decodeIfPresent(Double.self, forKey: .deltaEGoodMax) ?? d.deltaEGoodMax
+        deltaEWarningMax = try c.decodeIfPresent(Double.self, forKey: .deltaEWarningMax) ?? d.deltaEWarningMax
+        enableI1Pro2Leds = try c.decodeIfPresent(Bool.self, forKey: .enableI1Pro2Leds) ?? d.enableI1Pro2Leds
+        calibrationStaleDays = try c.decodeIfPresent(Int.self, forKey: .calibrationStaleDays) ?? d.calibrationStaleDays
+        defaultInstallLocation = try c.decodeIfPresent(InstallLocation.self, forKey: .defaultInstallLocation) ?? d.defaultInstallLocation
+        askBeforeOverwriteProfile = try c.decodeIfPresent(Bool.self, forKey: .askBeforeOverwriteProfile) ?? d.askBeforeOverwriteProfile
+        openColorPanelAfterInstall = try c.decodeIfPresent(Bool.self, forKey: .openColorPanelAfterInstall) ?? d.openColorPanelAfterInstall
+
+        // Per-element decode: typed presets win; a legacy M1 shape
+        // ({"name","values"}) migrates; unconvertible entries are
+        // skipped so one bad record never drops the array.
+        let elements = (try? c.decodeIfPresent(
+            [FailableDecodable<AnyPreset>].self, forKey: .customPresets
+        )) ?? nil
+        var migrated: [ProfilingPreset] = []
+        for (index, element) in (elements ?? []).enumerated() {
+            switch element.value {
+            case .typed(let preset):
+                migrated.append(preset)
+            case .legacy(let legacy):
+                if let converted = ProfilingPreset(migrating: legacy, index: index) {
+                    migrated.append(converted)
+                } else {
+                    AppLogger(category: "settings").warn(
+                        "Skipped unmigratable legacy preset: \(legacy.name)"
+                    )
+                }
+            case .none:
+                AppLogger(category: "settings").warn(
+                    "Skipped malformed preset entry at index \(index)"
+                )
+            }
+        }
+        customPresets = migrated
+    }
+
     /// UI-facing validation. Strings are part of the contract (issue #5).
     public static let errorNegativeDeltaE = "ΔE thresholds cannot be negative."
     public static let errorThresholdOrder =
@@ -113,3 +175,77 @@ public struct AppSettings: Codable, Equatable, Sendable {
 
     public var isValid: Bool { validate().isEmpty }
 }
+
+extension ProfilingPreset {
+
+    /// Migrates a legacy M1 `CustomPreset` (`name` + string values) to
+    /// the typed schema. Known keys are coerced; anything else is
+    /// ignored. Returns `nil` only when the name is unusable — a
+    /// deterministic `custom-{index}-{slug}` id is always produced.
+    init?(migrating legacy: CustomPreset, index: Int) {
+        let trimmedName = legacy.name.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmedName.isEmpty else { return nil }
+
+        let v = legacy.values
+        func int(_ key: String) -> Int? {
+            v[key].flatMap { Int($0.trimmingCharacters(in: .whitespaces)) }
+        }
+        func double(_ key: String) -> Double? {
+            v[key].flatMap { Double($0.trimmingCharacters(in: .whitespaces)) }
+        }
+        func bool(_ key: String) -> Bool? {
+            v[key].flatMap { s in
+                switch s.trimmingCharacters(in: .whitespaces).lowercased() {
+                case "true", "1", "yes": return true
+                case "false", "0", "no": return false
+                default: return nil
+                }
+            }
+        }
+        func string(_ key: String) -> String? {
+            v[key].map { $0.trimmingCharacters(in: .whitespaces) }
+                .flatMap { $0.isEmpty ? nil : $0 }
+        }
+
+        let slug = trimmedName.lowercased()
+            .map { $0.isLetter || $0.isNumber ? $0 : "-" }
+            .reduce(into: "") { $0.append($1) }
+
+        self.init(
+            id: "custom-\(index)-\(slug)",
+            name: trimmedName,
+            description: string("description") ?? "",
+            colourSpace: string("colour_space")?.lowercased() ?? "rgb",
+            patchCount: int("patch_count") ?? 800,
+            whitePatches: int("white_patches") ?? 4,
+            blackPatches: int("black_patches") ?? 4,
+            greySteps: int("grey_steps"),
+            singleChannelSteps: int("single_channel_steps"),
+            neutralSteps: int("neutral_steps"),
+            neutralConcentration: double("neutral_concentration"),
+            preconditioningProfile: string("preconditioning_profile"),
+            ofpsHighQuality: bool("ofps_high_quality"),
+            ofpsAdaptation: double("ofps_adaptation"),
+            fullSpreadAlgorithm: string("full_spread_algorithm"),
+            totalInkLimit: int("total_ink_limit"),
+            darkEmphasis: double("dark_emphasis"),
+            devicePower: double("device_power"),
+            instrument: string("instrument") ?? "i1",
+            pageSize: string("page_size") ?? "A4",
+            bitDepth: int("bit_depth") ?? 8,
+            dpi: int("dpi") ?? 300,
+            randomSeed: int("random_seed"),
+            noRandomize: bool("no_randomize"),
+            calibrationFile: string("calibration_file"),
+            applyCalibration: bool("apply_calibration"),
+            colprofAlgorithm: string("colprof_algorithm"),
+            colprofQuality: string("colprof_quality"),
+            colprofIntent: string("colprof_intent"),
+            colprofFwa: string("colprof_fwa"),
+            colprofIlluminant: string("colprof_illuminant"),
+            colprofObserver: string("colprof_observer"),
+            colprofInputViewingCond: string("colprof_input_viewing_cond"),
+            colprofOutputViewingCond: string("colprof_output_viewing_cond")
+        )
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Settings/PresetCatalog.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/PresetCatalog.swift
new file mode 100644
index 0000000..f404331
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/PresetCatalog.swift
@@ -0,0 +1,118 @@
+import Foundation
+
+/// Built-in presets shipped with the app (docs/22 §Built-in presets).
+/// All four: instrument `i1`, FWA `D50`, random seed `1`,
+/// `no_randomize == false`, colprof algorithm `l`.
+///
+/// Built-ins cannot be deleted; custom presets overlay by `id`.
+public enum PresetCatalog {
+
+    /// `preset-std-rgb` — Standard RGB Photo (800 patches).
+    public static let standardRGB = ProfilingPreset(
+        id: "preset-std-rgb",
+        name: "Standard RGB Photo (800 patches)",
+        description: "Everyday RGB driver printing — 800 patches on A4 at 300 dpi.",
+        colourSpace: "rgb",
+        patchCount: 800,
+        whitePatches: 4,
+        blackPatches: 4,
+        instrument: "i1",
+        pageSize: "A4",
+        bitDepth: 8,
+        dpi: 300,
+        randomSeed: 1,
+        noRandomize: false,
+        colprofAlgorithm: "l",
+        colprofQuality: "m",
+        colprofFwa: "D50"
+    )
+
+    /// `preset-hq-cmyk` — High-Gamut CMYK Proofing (1500 patches).
+    public static let highQualityCMYK = ProfilingPreset(
+        id: "preset-hq-cmyk",
+        name: "High-Gamut CMYK Proofing (1500 patches)",
+        description: "RIP-driven CMYK output — 1500 patches on A3, 16-bit, 320% ink limit.",
+        colourSpace: "cmyk",
+        patchCount: 1500,
+        whitePatches: 4,
+        blackPatches: 8,
+        totalInkLimit: 320,
+        instrument: "i1",
+        pageSize: "A3",
+        bitDepth: 16,
+        dpi: 300,
+        randomSeed: 1,
+        noRandomize: false,
+        colprofAlgorithm: "l",
+        colprofQuality: "h",
+        colprofFwa: "D50"
+    )
+
+    /// `preset-draft-rgb` — Fast RGB Draft (400 patches, **150 dpi**).
+    public static let draftRGB = ProfilingPreset(
+        id: "preset-draft-rgb",
+        name: "Fast RGB Draft (400 patches)",
+        description: "Quick sanity check — 400 patches on A4 at 150 dpi.",
+        colourSpace: "rgb",
+        patchCount: 400,
+        whitePatches: 4,
+        blackPatches: 4,
+        instrument: "i1",
+        pageSize: "A4",
+        bitDepth: 8,
+        dpi: 150,
+        randomSeed: 1,
+        noRandomize: false,
+        colprofAlgorithm: "l",
+        colprofQuality: "l",
+        colprofFwa: "D50"
+    )
+
+    /// `preset-ultra-rgb` — Ultra Precision RGB (2500 patches, `-G`).
+    public static let ultraRGB = ProfilingPreset(
+        id: "preset-ultra-rgb",
+        name: "Ultra Precision RGB (2500 patches)",
+        description: "Maximum coverage — 2500 patches on A3, 16-bit, OFPS high quality.",
+        colourSpace: "rgb",
+        patchCount: 2500,
+        whitePatches: 6,
+        blackPatches: 6,
+        ofpsHighQuality: true,
+        instrument: "i1",
+        pageSize: "A3",
+        bitDepth: 16,
+        dpi: 300,
+        randomSeed: 1,
+        noRandomize: false,
+        colprofAlgorithm: "l",
+        colprofQuality: "u",
+        colprofFwa: "D50"
+    )
+
+    public static let builtIns: [ProfilingPreset] = [
+        standardRGB, highQualityCMYK, draftRGB, ultraRGB,
+    ]
+
+    public static let builtInIDs: Set<String> = Set(builtIns.map(\.id))
+
+    public static func isBuiltIn(_ id: String) -> Bool {
+        builtInIDs.contains(id)
+    }
+
+    /// Built-ins plus custom presets, with custom entries overlaying by
+    /// `id` (a custom preset with a built-in id replaces that entry in
+    /// place — the built-in is still not deletable).
+    public static func all(custom: [ProfilingPreset]) -> [ProfilingPreset] {
+        var result = builtIns
+        var seen = builtInIDs
+        for custom in custom {
+            if let idx = result.firstIndex(where: { $0.id == custom.id }) {
+                result[idx] = custom
+            } else if !seen.contains(custom.id) {
+                result.append(custom)
+                seen.insert(custom.id)
+            }
+        }
+        return result
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Settings/PresetStore.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/PresetStore.swift
new file mode 100644
index 0000000..eec99f3
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/PresetStore.swift
@@ -0,0 +1,98 @@
+import Foundation
+
+/// CRUD + import/export for profiling presets on top of `SettingsStore`
+/// (docs/22 §Built-in presets, issue #11).
+///
+/// - `all()` = built-ins overlaid by custom presets (by `id`).
+/// - Built-ins are never written to `settings.json` and cannot be
+///   deleted or overwritten by `saveCustom` (a custom id that collides
+///   with a built-in still overlays at read time, per spec).
+/// - Import/export is single-preset JSON with schema validation.
+/// - Imported names/descriptions are untrusted: callers must render
+///   them with `Text`, never HTML (#114).
+public final class PresetStore: Sendable {
+
+    public let settingsStore: SettingsStore
+
+    public init(settingsStore: SettingsStore = SettingsStore()) {
+        self.settingsStore = settingsStore
+    }
+
+    /// All presets: built-ins overlaid by customs, catalog order.
+    public func all() -> [ProfilingPreset] {
+        PresetCatalog.all(custom: settingsStore.load().customPresets)
+    }
+
+    /// Custom presets only, as persisted.
+    public func customs() -> [ProfilingPreset] {
+        settingsStore.load().customPresets
+    }
+
+    /// Insert or replace a custom preset (matched by `id`). Throws
+    /// `PresetStoreError.builtIn` when the id belongs to a built-in —
+    /// built-ins are immutable. Validates before persisting.
+    public func saveCustom(_ preset: ProfilingPreset) throws {
+        let validated = try preset.validated()
+        guard !PresetCatalog.isBuiltIn(validated.id) else {
+            throw PresetStoreError.builtInImmutable(validated.id)
+        }
+        var settings = settingsStore.load()
+        if let idx = settings.customPresets.firstIndex(where: { $0.id == validated.id }) {
+            settings.customPresets[idx] = validated
+        } else {
+            settings.customPresets.append(validated)
+        }
+        try settingsStore.save(settings)
+    }
+
+    /// Deletes a custom preset by id. Returns false when the id is a
+    /// built-in (undeletable) or no custom preset with that id exists.
+    @discardableResult
+    public func deleteCustom(id: String) throws -> Bool {
+        guard !PresetCatalog.isBuiltIn(id) else { return false }
+        var settings = settingsStore.load()
+        let before = settings.customPresets.count
+        settings.customPresets.removeAll { $0.id == id }
+        guard settings.customPresets.count != before else { return false }
+        try settingsStore.save(settings)
+        return true
+    }
+
+    /// Single-preset pretty JSON export.
+    public func export(_ preset: ProfilingPreset) throws -> Data {
+        let encoder = JSONEncoder()
+        encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
+        return try encoder.encode(preset)
+    }
+
+    /// Parses + validates a preset from JSON. The preset is assigned a
+    /// fresh custom id when its id is empty or collides with a built-in.
+    /// Does **not** persist — call `saveCustom` to keep it.
+    public func `import`(_ data: Data) throws -> ProfilingPreset {
+        let decoded: ProfilingPreset
+        do {
+            decoded = try JSONDecoder().decode(ProfilingPreset.self, from: data)
+        } catch {
+            throw PresetStoreError.invalidJSON(error.localizedDescription)
+        }
+        var preset = try decoded.validated()
+        if preset.id.isEmpty || PresetCatalog.isBuiltIn(preset.id) {
+            preset.id = "custom-\(UUID().uuidString.lowercased())"
+        }
+        return preset
+    }
+
+    public enum PresetStoreError: LocalizedError, Equatable {
+        case builtInImmutable(String)
+        case invalidJSON(String)
+
+        public var errorDescription: String? {
+            switch self {
+            case .builtInImmutable(let id):
+                return "Built-in preset \"\(id)\" cannot be modified or deleted."
+            case .invalidJSON(let reason):
+                return "Not a valid preset file: \(reason)"
+            }
+        }
+    }
+}
diff --git a/Packages/ICCeryCore/Sources/ICCeryCore/Settings/ProfilingPreset.swift b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/ProfilingPreset.swift
new file mode 100644
index 0000000..c0aad66
--- /dev/null
+++ b/Packages/ICCeryCore/Sources/ICCeryCore/Settings/ProfilingPreset.swift
@@ -0,0 +1,272 @@
+import Foundation
+
+/// A profiling preset: a complete snapshot of the Stage 1/2 form plus
+/// the Stage 4 fields that are stored now and applied in issue 23
+/// (docs/22 §ProfilingPreset).
+///
+/// snake_case keys match the v1 JSON schema so import/export stays
+/// compatible. Identity + Stage 1/2 core fields are required; every
+/// other field is optional-defaulted. Unknown keys are ignored on
+/// decode; missing required fields fail.
+public struct ProfilingPreset: Codable, Equatable, Sendable, Identifiable {
+
+    // Identity
+    public var id: String
+    public var name: String
+    public var description: String
+
+    // Stage 1 (required core)
+    public var colourSpace: String          // "rgb" | "cmyk"
+    public var patchCount: Int
+    public var whitePatches: Int
+    public var blackPatches: Int
+
+    // Stage 1 advanced (optional)
+    public var greySteps: Int?
+    public var singleChannelSteps: Int?
+    public var neutralSteps: Int?
+    public var neutralConcentration: Double?
+    public var preconditioningProfile: String?
+    public var ofpsHighQuality: Bool?
+    public var ofpsAdaptation: Double?
+    /// Stored as the flag letter: "ofps" or "t","r","R","q","Q","i","I".
+    public var fullSpreadAlgorithm: String?
+    public var totalInkLimit: Int?
+    public var darkEmphasis: Double?
+    public var devicePower: Double?
+
+    // Stage 2 (required core)
+    public var instrument: String
+    public var pageSize: String
+    public var bitDepth: Int
+    public var dpi: Int
+    public var randomSeed: Int?
+    public var noRandomize: Bool?
+
+    // Stage 0 / 2 calibration
+    public var calibrationFile: String?
+    public var applyCalibration: Bool?
+
+    // Stage 4 (stored now, applied by issue 23)
+    public var colprofAlgorithm: String?
+    public var colprofQuality: String?
+    public var colprofIntent: String?
+    public var colprofFwa: String?
+    public var colprofIlluminant: String?
+    public var colprofObserver: String?
+    public var colprofInputViewingCond: String?
+    public var colprofOutputViewingCond: String?
+
+    public init(
+        id: String,
+        name: String,
+        description: String = "",
+        colourSpace: String = "rgb",
+        patchCount: Int = 800,
+        whitePatches: Int = 4,
+        blackPatches: Int = 4,
+        greySteps: Int? = nil,
+        singleChannelSteps: Int? = nil,
+        neutralSteps: Int? = nil,
+        neutralConcentration: Double? = nil,
+        preconditioningProfile: String? = nil,
+        ofpsHighQuality: Bool? = nil,
+        ofpsAdaptation: Double? = nil,
+        fullSpreadAlgorithm: String? = nil,
+        totalInkLimit: Int? = nil,
+        darkEmphasis: Double? = nil,
+        devicePower: Double? = nil,
+        instrument: String = "i1",
+        pageSize: String = "A4",
+        bitDepth: Int = 8,
+        dpi: Int = 300,
+        randomSeed: Int? = 1,
+        noRandomize: Bool? = false,
+        calibrationFile: String? = nil,
+        applyCalibration: Bool? = nil,
+        colprofAlgorithm: String? = nil,
+        colprofQuality: String? = nil,
+        colprofIntent: String? = nil,
+        colprofFwa: String? = nil,
+        colprofIlluminant: String? = nil,
+        colprofObserver: String? = nil,
+        colprofInputViewingCond: String? = nil,
+        colprofOutputViewingCond: String? = nil
+    ) {
+        self.id = id
+        self.name = name
+        self.description = description
+        self.colourSpace = colourSpace
+        self.patchCount = patchCount
+        self.whitePatches = whitePatches
+        self.blackPatches = blackPatches
+        self.greySteps = greySteps
+        self.singleChannelSteps = singleChannelSteps
+        self.neutralSteps = neutralSteps
+        self.neutralConcentration = neutralConcentration
+        self.preconditioningProfile = preconditioningProfile
+        self.ofpsHighQuality = ofpsHighQuality
+        self.ofpsAdaptation = ofpsAdaptation
+        self.fullSpreadAlgorithm = fullSpreadAlgorithm
+        self.totalInkLimit = totalInkLimit
+        self.darkEmphasis = darkEmphasis
+        self.devicePower = devicePower
+        self.instrument = instrument
+        self.pageSize = pageSize
+        self.bitDepth = bitDepth
+        self.dpi = dpi
+        self.randomSeed = randomSeed
+        self.noRandomize = noRandomize
+        self.calibrationFile = calibrationFile
+        self.applyCalibration = applyCalibration
+        self.colprofAlgorithm = colprofAlgorithm
+        self.colprofQuality = colprofQuality
+        self.colprofIntent = colprofIntent
+        self.colprofFwa = colprofFwa
+        self.colprofIlluminant = colprofIlluminant
+        self.colprofObserver = colprofObserver
+        self.colprofInputViewingCond = colprofInputViewingCond
+        self.colprofOutputViewingCond = colprofOutputViewingCond
+    }
+
+    enum CodingKeys: String, CodingKey {
+        case id, name, description
+        case colourSpace = "colour_space"
+        case patchCount = "patch_count"
+        case whitePatches = "white_patches"
+        case blackPatches = "black_patches"
+        case greySteps = "grey_steps"
+        case singleChannelSteps = "single_channel_steps"
+        case neutralSteps = "neutral_steps"
+        case neutralConcentration = "neutral_concentration"
+        case preconditioningProfile = "preconditioning_profile"
+        case ofpsHighQuality = "ofps_high_quality"
+        case ofpsAdaptation = "ofps_adaptation"
+        case fullSpreadAlgorithm = "full_spread_algorithm"
+        case totalInkLimit = "total_ink_limit"
+        case darkEmphasis = "dark_emphasis"
+        case devicePower = "device_power"
+        case instrument
+        case pageSize = "page_size"
+        case bitDepth = "bit_depth"
+        case dpi
+        case randomSeed = "random_seed"
+        case noRandomize = "no_randomize"
+        case calibrationFile = "calibration_file"
+        case applyCalibration = "apply_calibration"
+        case colprofAlgorithm = "colprof_algorithm"
+        case colprofQuality = "colprof_quality"
+        case colprofIntent = "colprof_intent"
+        case colprofFwa = "colprof_fwa"
+        case colprofIlluminant = "colprof_illuminant"
+        case colprofObserver = "colprof_observer"
+        case colprofInputViewingCond = "colprof_input_viewing_cond"
+        case colprofOutputViewingCond = "colprof_output_viewing_cond"
+    }
+
+    /// Strict decode: required identity + Stage 1/2 core fields must be
+    /// present; optionals default to nil. Unknown keys are ignored.
+    public init(from decoder: Decoder) throws {
+        let c = try decoder.container(keyedBy: CodingKeys.self)
+        id = try c.decode(String.self, forKey: .id)
+        name = try c.decode(String.self, forKey: .name)
+        description = try c.decodeIfPresent(String.self, forKey: .description) ?? ""
+        colourSpace = try c.decode(String.self, forKey: .colourSpace)
+        patchCount = try c.decode(Int.self, forKey: .patchCount)
+        whitePatches = try c.decode(Int.self, forKey: .whitePatches)
+        blackPatches = try c.decode(Int.self, forKey: .blackPatches)
+        greySteps = try c.decodeIfPresent(Int.self, forKey: .greySteps)
+        singleChannelSteps = try c.decodeIfPresent(Int.self, forKey: .singleChannelSteps)
+        neutralSteps = try c.decodeIfPresent(Int.self, forKey: .neutralSteps)
+        neutralConcentration = try c.decodeIfPresent(Double.self, forKey: .neutralConcentration)
+        preconditioningProfile = try c.decodeIfPresent(String.self, forKey: .preconditioningProfile)
+        ofpsHighQuality = try c.decodeIfPresent(Bool.self, forKey: .ofpsHighQuality)
+        ofpsAdaptation = try c.decodeIfPresent(Double.self, forKey: .ofpsAdaptation)
+        fullSpreadAlgorithm = try c.decodeIfPresent(String.self, forKey: .fullSpreadAlgorithm)
+        totalInkLimit = try c.decodeIfPresent(Int.self, forKey: .totalInkLimit)
+        darkEmphasis = try c.decodeIfPresent(Double.self, forKey: .darkEmphasis)
+        devicePower = try c.decodeIfPresent(Double.self, forKey: .devicePower)
+        instrument = try c.decode(String.self, forKey: .instrument)
+        pageSize = try c.decode(String.self, forKey: .pageSize)
+        bitDepth = try c.decode(Int.self, forKey: .bitDepth)
+        dpi = try c.decode(Int.self, forKey: .dpi)
+        randomSeed = try c.decodeIfPresent(Int.self, forKey: .randomSeed)
+        noRandomize = try c.decodeIfPresent(Bool.self, forKey: .noRandomize)
+        calibrationFile = try c.decodeIfPresent(String.self, forKey: .calibrationFile)
+        applyCalibration = try c.decodeIfPresent(Bool.self, forKey: .applyCalibration)
+        colprofAlgorithm = try c.decodeIfPresent(String.self, forKey: .colprofAlgorithm)
+        colprofQuality = try c.decodeIfPresent(String.self, forKey: .colprofQuality)
+        colprofIntent = try c.decodeIfPresent(String.self, forKey: .colprofIntent)
+        colprofFwa = try c.decodeIfPresent(String.self, forKey: .colprofFwa)
+        colprofIlluminant = try c.decodeIfPresent(String.self, forKey: .colprofIlluminant)
+        colprofObserver = try c.decodeIfPresent(String.self, forKey: .colprofObserver)
+        colprofInputViewingCond = try c.decodeIfPresent(String.self, forKey: .colprofInputViewingCond)
+        colprofOutputViewingCond = try c.decodeIfPresent(String.self, forKey: .colprofOutputViewingCond)
+    }
+
+    // MARK: - Validation (import path)
+
+    public enum ValidationError: LocalizedError, Equatable {
+        case emptyID
+        case emptyName
+        case invalidColourSpace(String)
+        case invalidPatchCount(Int)
+        case invalidBitDepth(Int)
+        case invalidDPI(Int)
+        case emptyPageSize
+        case emptyInstrument
+
+        public var errorDescription: String? {
+            switch self {
+            case .emptyID: return "Preset is missing an id."
+            case .emptyName: return "Preset is missing a name."
+            case .invalidColourSpace(let v):
+                return "colour_space must be \"rgb\" or \"cmyk\", got \"\(v)\"."
+            case .invalidPatchCount(let v):
+                return "patch_count must be positive, got \(v)."
+            case .invalidBitDepth(let v):
+                return "bit_depth must be 8 or 16, got \(v)."
+            case .invalidDPI(let v):
+                return "dpi must be between 72 and 600, got \(v)."
+            case .emptyPageSize: return "page_size is empty."
+            case .emptyInstrument: return "instrument is empty."
+            }
+        }
+    }
+
+    /// Validates the required fields for import / catalog use.
+    /// `colourSpace` is normalized to lowercase before comparison.
+    @discardableResult
+    public func validated() throws -> ProfilingPreset {
+        var p = self
+        p.id = id.trimmingCharacters(in: .whitespacesAndNewlines)
+        p.name = name.trimmingCharacters(in: .whitespacesAndNewlines)
+        p.colourSpace = colourSpace.lowercased()
+        guard !p.id.isEmpty else { throw ValidationError.emptyID }
+        guard !p.name.isEmpty else { throw ValidationError.emptyName }
+        guard p.colourSpace == "rgb" || p.colourSpace == "cmyk" else {
+            throw ValidationError.invalidColourSpace(colourSpace)
+        }
+        guard p.patchCount > 0 else { throw ValidationError.invalidPatchCount(patchCount) }
+        guard p.bitDepth == 8 || p.bitDepth == 16 else {
+            throw ValidationError.invalidBitDepth(bitDepth)
+        }
+        guard (72...600).contains(p.dpi) else { throw ValidationError.invalidDPI(dpi) }
+        guard !p.pageSize.trimmingCharacters(in: .whitespaces).isEmpty else {
+            throw ValidationError.emptyPageSize
+        }
+        guard !p.instrument.trimmingCharacters(in: .whitespaces).isEmpty else {
+            throw ValidationError.emptyInstrument
+        }
+        return p
+    }
+}
+
+/// Per-element non-throwing decode wrapper — one malformed preset entry
+/// must not drop the whole `custom_presets` array during migration.
+struct FailableDecodable<T: Decodable>: Decodable {
+    let value: T?
+    init(from decoder: Decoder) throws {
+        value = try? T(from: decoder)
+    }
+}
diff --git a/Sources/ICCery/AppEnvironment.swift b/Sources/ICCery/AppEnvironment.swift
new file mode 100644
index 0000000..00b796a
--- /dev/null
+++ b/Sources/ICCery/AppEnvironment.swift
@@ -0,0 +1,70 @@
+import Foundation
+import ICCeryCore
+
+/// App dependency container (docs/02). Production builds resolve the
+/// user's `argyll_binary_dir` override or bundled sidecars; DEBUG UI
+/// tests inject fixture binaries via `ICCERY_ARGYLL_BINARY_DIR` and
+/// redirect `AppPaths` via `ICCERY_TEST_ROOT`, so tests never touch the
+/// developer's settings, wizard state, or real Argyll install.
+struct AppEnvironment: Sendable {
+    let stateStore: WizardStateStore
+    let settingsStore: SettingsStore
+    let presetStore: PresetStore
+    let runner: ArgyllRunner
+
+    static func live(
+        environment: [String: String] = ProcessInfo.processInfo.environment
+    ) -> AppEnvironment {
+        let settingsStore = SettingsStore()
+        var overrideDir = settingsStore.load().argyllBinaryDir
+            .map { URL(fileURLWithPath: $0) }
+        #if DEBUG
+        if let dir = environment["ICCERY_ARGYLL_BINARY_DIR"], !dir.isEmpty {
+            overrideDir = URL(fileURLWithPath: dir)
+        }
+        #endif
+        return AppEnvironment(
+            stateStore: WizardStateStore(),
+            settingsStore: settingsStore,
+            presetStore: PresetStore(settingsStore: settingsStore),
+            runner: ArgyllRunner(
+                processManager: .shared,
+                binaryResolver: BinaryResolver(overrideDir: overrideDir)
+            )
+        )
+    }
+}
+
+/// DEBUG-only UI-test hooks. When `ICCERY_UI_TESTING=1` the workflow
+/// honours these env-provided paths instead of presenting modal panels
+/// (XCUITest cannot drive NSOpenPanel/NSSavePanel reliably). These are
+/// compiled out of release builds.
+enum UITestHooks {
+    private static var env: [String: String] {
+        ProcessInfo.processInfo.environment
+    }
+
+    static var isEnabled: Bool {
+        #if DEBUG
+        return env["ICCERY_UI_TESTING"] == "1"
+        #else
+        return false
+        #endif
+    }
+
+    /// `select_target_file` result (Stage 1 save picker).
+    static var saveTargetURL: URL? { url("ICCERY_TEST_SAVE_TARGET") }
+    /// `select_existing_target` result (`.ti1`/`.ti2` resume).
+    static var existingTargetURL: URL? { url("ICCERY_TEST_EXISTING_TARGET") }
+    /// `select_directory` result (working-directory browse).
+    static var workDirURL: URL? { url("ICCERY_TEST_WORKDIR") }
+    /// Preset import file.
+    static var presetImportURL: URL? { url("ICCERY_TEST_PRESET_IMPORT") }
+    /// Preset export destination.
+    static var presetExportURL: URL? { url("ICCERY_TEST_PRESET_EXPORT") }
+
+    private static func url(_ key: String) -> URL? {
+        guard let raw = env[key], !raw.isEmpty else { return nil }
+        return URL(fileURLWithPath: raw)
+    }
+}
diff --git a/Sources/ICCery/FileDialogService.swift b/Sources/ICCery/FileDialogService.swift
index d7b7a33..13e7c0c 100644
--- a/Sources/ICCery/FileDialogService.swift
+++ b/Sources/ICCery/FileDialogService.swift
@@ -80,6 +80,23 @@ final class FileDialogService {
              message: "Choose a calibration file (.cal)")
     }
 
+    /// `btnImportPreset` — open a `.json` preset file.
+    func selectPresetFile(startingAt start: URL? = nil) -> URL? {
+        open(extensions: ["json"], startingAt: start,
+             message: "Import a profiling preset (.json)")
+    }
+
+    /// `btnExportActivePreset` — save a `.json` preset file.
+    func selectPresetSavePath(name: String, startingAt start: URL? = nil) -> URL? {
+        let panel = NSSavePanel()
+        panel.nameFieldStringValue = "\(name).json"
+        panel.allowedContentTypes = utTypes(["json"])
+        panel.allowsOtherFileTypes = false
+        panel.directoryURL = start
+        panel.message = "Export this preset as JSON"
+        return run(panel)
+    }
+
     // MARK: - Internals (private — not a shared public picker API)
 
     private func open(
diff --git a/Sources/ICCery/ICCeryApp.swift b/Sources/ICCery/ICCeryApp.swift
index a61a29d..fb5eeeb 100644
--- a/Sources/ICCery/ICCeryApp.swift
+++ b/Sources/ICCery/ICCeryApp.swift
@@ -5,19 +5,21 @@ import SwiftUI
 @main
 struct ICCeryApp: App {
     @NSApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate
-    @State private var model = WizardViewModel()
+    @State private var workflow: TargetWorkflowViewModel
 
     init() {
+        let environment = AppEnvironment.live()
+        _workflow = State(initialValue: TargetWorkflowViewModel(environment: environment))
         try? AppPaths.ensureDirectories()
         // Log level is runtime state — apply persisted settings at
         // startup (#158); the Settings sheet re-applies on save.
-        LogSink.shared.applySettings(SettingsStore().load())
+        LogSink.shared.applySettings(environment.settingsStore.load())
     }
 
     var body: some Scene {
         // Single fixed window (docs/21 §Shell: 1280×800, min 1100×700).
         Window("ICCery", id: "main") {
-            RootView(model: model)
+            RootView(workflow: workflow)
                 .frame(minWidth: 1100, minHeight: 700)
                 .preferredColorScheme(.dark)
         }
diff --git a/Sources/ICCery/NoticeBanner.swift b/Sources/ICCery/NoticeBanner.swift
index c0bfb67..4490475 100644
--- a/Sources/ICCery/NoticeBanner.swift
+++ b/Sources/ICCery/NoticeBanner.swift
@@ -42,6 +42,7 @@ struct NoticeBanner: View {
                 .font(.callout)
                 .foregroundStyle(Theme.text)
                 .lineLimit(3)
+                .accessibilityIdentifier("noticeText")
             Spacer()
             Button(action: onClose) {
                 Image(systemName: "xmark")
diff --git a/Sources/ICCery/PresetDialogs.swift b/Sources/ICCery/PresetDialogs.swift
new file mode 100644
index 0000000..e9781a9
--- /dev/null
+++ b/Sources/ICCery/PresetDialogs.swift
@@ -0,0 +1,92 @@
+import SwiftUI
+import ICCeryCore
+
+/// `#savePresetDialog` — save the live Stage 1/2 form as a custom
+/// preset (issue #11). Names/descriptions render via `Text` only (#114).
+struct SavePresetDialog: View {
+    @Bindable var workflow: TargetWorkflowViewModel
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 14) {
+            Text("Save Preset").font(.title3).foregroundStyle(Theme.text)
+            TextField("Name", text: $workflow.savePresetName)
+                .textFieldStyle(.roundedBorder)
+                .accessibilityIdentifier("savePresetName")
+            TextField("Description (optional)", text: $workflow.savePresetDesc)
+                .textFieldStyle(.roundedBorder)
+                .accessibilityIdentifier("savePresetDesc")
+            HStack {
+                Spacer()
+                Button("Cancel") { workflow.showingSavePreset = false }
+                    .accessibilityIdentifier("btnCloseSavePresetDialog")
+                Button("Save") { workflow.saveCurrentAsPreset() }
+                    .accessibilityIdentifier("btnConfirmSavePreset")
+                    .disabled(workflow.savePresetName
+                        .trimmingCharacters(in: .whitespaces).isEmpty)
+            }
+        }
+        .padding(20)
+        .frame(width: 380)
+        .background(Theme.background)
+        .accessibilityElement(children: .contain)
+        .accessibilityIdentifier("savePresetDialog")
+    }
+}
+
+/// `#managePresetsDialog` — list, delete (custom only), import, export.
+struct ManagePresetsDialog: View {
+    @Bindable var workflow: TargetWorkflowViewModel
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            Text("Manage Presets").font(.title3).foregroundStyle(Theme.text)
+            List {
+                ForEach(workflow.presets) { preset in
+                    HStack {
+                        VStack(alignment: .leading, spacing: 2) {
+                            Text(preset.name).foregroundStyle(Theme.text)
+                            if !preset.description.isEmpty {
+                                Text(preset.description)
+                                    .font(.caption).foregroundStyle(.secondary)
+                            }
+                        }
+                        Spacer()
+                        if PresetCatalog.isBuiltIn(preset.id) {
+                            Text("Built-in")
+                                .font(.caption).foregroundStyle(.secondary)
+                        } else {
+                            Button("Export") { workflow.exportPreset(preset) }
+                                .accessibilityIdentifier(
+                                    "btnExportPreset-\(preset.id)")
+                            Button("Delete", role: .destructive) {
+                                workflow.deletePreset(preset)
+                            }
+                            .accessibilityIdentifier("btnDeletePreset-\(preset.id)")
+                        }
+                    }
+                    .accessibilityElement(children: .contain)
+                    .accessibilityIdentifier("presetRow-\(preset.id)")
+                }
+            }
+            .accessibilityIdentifier("managePresetsList")
+            .frame(minHeight: 240)
+            HStack {
+                Button("Import…") { workflow.importPreset() }
+                    .accessibilityIdentifier("btnImportPreset")
+                if let selected = workflow.selectedPreset,
+                   !PresetCatalog.isBuiltIn(selected.id) {
+                    Button("Export Active") { workflow.exportPreset(selected) }
+                        .accessibilityIdentifier("btnExportActivePreset")
+                }
+                Spacer()
+                Button("Close") { workflow.showingManagePresets = false }
+                    .accessibilityIdentifier("btnCloseManagePresetsDialog")
+            }
+        }
+        .padding(20)
+        .frame(width: 480)
+        .background(Theme.background)
+        .accessibilityElement(children: .contain)
+        .accessibilityIdentifier("managePresetsDialog")
+    }
+}
diff --git a/Sources/ICCery/RootView.swift b/Sources/ICCery/RootView.swift
index 3a38f5c..b7b2141 100644
--- a/Sources/ICCery/RootView.swift
+++ b/Sources/ICCery/RootView.swift
@@ -1,17 +1,20 @@
 import AppKit
 import SwiftUI
+import ICCeryCore
 
 /// Root layout: 270 pt sidebar + main stage area with the notification
 /// banner pinned to the top (docs/21 §Shell).
 struct RootView: View {
-    @Bindable var model: WizardViewModel
+    @Bindable var workflow: TargetWorkflowViewModel
     @State private var showingSettings = false
     @State private var showingAbout = false
 
+    private var model: WizardViewModel { workflow.wizard }
+
     var body: some View {
         HStack(spacing: 0) {
             SidebarView(
-                model: model,
+                workflow: workflow,
                 onOpenSettings: { showingSettings = true },
                 onOpenAbout: { showingAbout = true }
             )
@@ -24,7 +27,7 @@ struct RootView: View {
                 if let notice = model.notice {
                     NoticeBanner(notice: notice, onClose: model.dismissNotice)
                 }
-                StagePlaceholderView(stage: model.stage)
+                stageContent
             }
         }
         .frame(minWidth: 1100, minHeight: 700)
@@ -39,10 +42,44 @@ struct RootView: View {
         .sheet(isPresented: $showingSettings) {
             SettingsView()
         }
+        .sheet(isPresented: $workflow.showingSavePreset) {
+            SavePresetDialog(workflow: workflow)
+        }
+        .sheet(isPresented: $workflow.showingManagePresets) {
+            ManagePresetsDialog(workflow: workflow)
+        }
         .alert("ICCery 2.0.0", isPresented: $showingAbout) {
             Button("OK") {}
         } message: {
             Text("Native macOS printer profiling workstation.\nFull About dialog lands in issue #31.")
         }
     }
+
+    @ViewBuilder
+    private var stageContent: some View {
+        switch model.stage {
+        case .generate:
+            Stage1View(workflow: workflow)
+        case .layOutPrint:
+            Stage2View(workflow: workflow)
+        case .measure:
+            // Stage 3 stays a shell until M4, but a .ti2 resume still
+            // lands here — show the persisted state (#8, issue #140).
+            VStack(spacing: 16) {
+                if workflow.resumedFromTi2 {
+                    Label("Resumed from .ti2", systemImage: "arrow.uturn.right")
+                        .font(.callout)
+                        .foregroundStyle(Theme.accent)
+                        .accessibilityIdentifier("stage3LoadedTargetBanner")
+                }
+                Text(model.basename)
+                    .font(.title3)
+                    .foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("stage3TargetBasename")
+                StagePlaceholderView(stage: model.stage)
+            }
+        default:
+            StagePlaceholderView(stage: model.stage)
+        }
+    }
 }
diff --git a/Sources/ICCery/SidebarView.swift b/Sources/ICCery/SidebarView.swift
index 7774bed..f2ed065 100644
--- a/Sources/ICCery/SidebarView.swift
+++ b/Sources/ICCery/SidebarView.swift
@@ -4,10 +4,12 @@ import ICCeryCore
 /// 270 pt sidebar (docs/21 §Shell): logo, settings/about buttons, preset
 /// select, Calibrate Printer + status chip, and the 1–5 stepper.
 struct SidebarView: View {
-    @Bindable var model: WizardViewModel
+    @Bindable var workflow: TargetWorkflowViewModel
     var onOpenSettings: () -> Void
     var onOpenAbout: () -> Void
 
+    private var model: WizardViewModel { workflow.wizard }
+
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {
             HStack {
@@ -31,16 +33,38 @@ struct SidebarView: View {
 
             Divider().overlay(Theme.border)
 
-            // Preset select (`#presetSelect`). Disabled until the preset
-            // engine lands in issue #11.
-            Picker("Preset", selection: .constant("none")) {
+            // Preset select (`#presetSelect`) — issue #11. Selection
+            // applies the preset immediately; names render via Text only.
+            Picker("Preset", selection: Binding(
+                get: { workflow.selectedPresetID },
+                set: { id in
+                    if id == "none" {
+                        workflow.selectedPresetID = "none"
+                    } else if let preset = workflow.presets.first(where: { $0.id == id }) {
+                        workflow.applyPreset(preset)
+                    }
+                }
+            )) {
                 Text("No preset").tag("none")
+                ForEach(workflow.presets) { preset in
+                    Text(preset.name).tag(preset.id)
+                }
             }
             .pickerStyle(.menu)
-            .disabled(true)
+            .accessibilityIdentifier("presetSelect")
             .padding(.horizontal, 12)
             .padding(.vertical, 8)
 
+            HStack(spacing: 8) {
+                Button("Save") { workflow.showingSavePreset = true }
+                    .accessibilityIdentifier("btnSavePresetModal")
+                Button("Manage") { workflow.showingManagePresets = true }
+                    .accessibilityIdentifier("btnOpenPresetsDialog")
+                Spacer()
+            }
+            .padding(.horizontal, 12)
+            .padding(.bottom, 8)
+
             // Calibrate Printer (`#btnCalibratePrinter`). Disabled until
             // Stage 0 lands in issue #29; `#calStatusChip` likewise.
             Button(action: { model.enterCalibration() }) {
diff --git a/Sources/ICCery/Stage1View.swift b/Sources/ICCery/Stage1View.swift
new file mode 100644
index 0000000..1db8cb3
--- /dev/null
+++ b/Sources/ICCery/Stage1View.swift
@@ -0,0 +1,256 @@
+import SwiftUI
+import ICCeryCore
+
+/// Stage 1 — `#stage-1` Generate Target (`targen` → `.ti1`, issue #7,
+/// docs/08). All documented element ids are wired as accessibility
+/// identifiers so the UI-test contract stays stable.
+struct Stage1View: View {
+    @Bindable var workflow: TargetWorkflowViewModel
+
+    var body: some View {
+        ScrollView {
+            VStack(alignment: .leading, spacing: 16) {
+                colourSpaceSection
+                patchSection
+                targetSection
+                advancedSection
+                actionRow
+                logSection
+            }
+            .padding(20)
+            .frame(maxWidth: .infinity, alignment: .leading)
+        }
+        .background(Theme.background)
+        .accessibilityIdentifier("stage-1")
+    }
+
+    // MARK: - Colour space (name="colourSpace")
+
+    private var colourSpaceSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            Text("Colour space").font(.headline).foregroundStyle(Theme.text)
+            Picker("Colour space", selection: $workflow.colourSpace) {
+                Text("RGB (print drivers)").tag(ColourSpace.rgb)
+                Text("CMYK (RIP output)").tag(ColourSpace.cmyk)
+            }
+            .pickerStyle(.segmented)
+            .accessibilityIdentifier("colourSpace")
+        }
+    }
+
+    // MARK: - Patch count + white/black
+
+    private var patchSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            Text("Patches").font(.headline).foregroundStyle(Theme.text)
+            HStack(spacing: 16) {
+                Picker("Patch count", selection: $workflow.patchPreset) {
+                    ForEach(PatchCountPreset.allCases, id: \.self) {
+                        Text($0.title).tag($0)
+                    }
+                }
+                .accessibilityIdentifier("patchCountPreset")
+                .frame(maxWidth: 220)
+
+                if workflow.patchPreset == .custom {
+                    TextField("Patches", value: $workflow.customPatchCount, format: .number)
+                        .textFieldStyle(.roundedBorder)
+                        .frame(width: 90)
+                        .accessibilityIdentifier("patchCountCustom")
+                }
+            }
+            HStack(spacing: 16) {
+                Stepper(value: $workflow.whitePatches, in: 0...50) {
+                    Text("White patches: \(workflow.whitePatches)")
+                }
+                .accessibilityIdentifier("whitePatches")
+                Stepper(value: $workflow.blackPatches, in: 0...50) {
+                    Text("Black patches: \(workflow.blackPatches)")
+                }
+                .accessibilityIdentifier("blackPatches")
+            }
+            .foregroundStyle(Theme.text)
+        }
+    }
+
+    // MARK: - Target file / working directory
+
+    private var targetSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            Text("Target file").font(.headline).foregroundStyle(Theme.text)
+            HStack(spacing: 8) {
+                TextField("Basename (no extension)", text: $workflow.targetBasename)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("targetBasename")
+                Button("Browse…") { workflow.browseForTargetFile() }
+                    .accessibilityIdentifier("btnBrowse")
+                Button("Working Dir…") { workflow.browseForWorkingDirectory() }
+                Button("Open Existing…") { workflow.openExistingTarget() }
+                    .accessibilityIdentifier("btnOpenExisting")
+                Button("Import Dataset…") { /* CGATS import — #94, later */ }
+                    .accessibilityIdentifier("btn-import-dataset")
+                    .disabled(true)
+            }
+            Text(workflow.targetDirectory?.path ?? "No working directory selected")
+                .font(.caption)
+                .foregroundStyle(.secondary)
+                .textSelection(.enabled)
+                .accessibilityIdentifier("selectedPathDisplay")
+        }
+    }
+
+    // MARK: - Advanced (#targenAdvancedDetails)
+
+    /// UI tests pre-expand the group — XCUI cannot reliably toggle a
+    /// macOS `DisclosureTriangle` (its click lands on the label).
+    @State private var advancedExpanded = UITestHooks.isEnabled
+
+    private var advancedSection: some View {
+        DisclosureGroup("Advanced", isExpanded: $advancedExpanded) {
+            VStack(alignment: .leading, spacing: 12) {
+                HStack(alignment: .top, spacing: 24) {
+                    VStack(alignment: .leading, spacing: 10) {
+                        optionalInt("Grey steps (-g)",
+                                    enabled: $workflow.greyStepsEnabled,
+                                    value: $workflow.greySteps)
+                        .accessibilityIdentifier("targenGreySteps")
+                        optionalInt("Single-channel steps (-s)",
+                                    enabled: $workflow.singleChannelEnabled,
+                                    value: $workflow.singleChannelSteps)
+                        .accessibilityIdentifier("targenSingleChannelSteps")
+                        optionalInt("Neutral steps (-n)",
+                                    enabled: $workflow.neutralStepsEnabled,
+                                    value: $workflow.neutralSteps)
+                        .accessibilityIdentifier("targenNeutralSteps")
+                        optionalDouble("Neutral concentration (-N)",
+                                       enabled: $workflow.neutralConcEnabled,
+                                       value: $workflow.neutralConcentration,
+                                       range: 0.0...1.0)
+                        .accessibilityIdentifier("targenNeutralConcentration")
+                        optionalDouble("OFPS adaptation (-A)",
+                                       enabled: $workflow.adaptationEnabled,
+                                       value: $workflow.adaptation,
+                                       range: 0.0...1.0)
+                        .accessibilityIdentifier("targenAdaptation")
+                    }
+                    VStack(alignment: .leading, spacing: 10) {
+                        HStack {
+                            TextField("Preconditioning profile",
+                                      text: Binding(
+                                        get: { workflow.preconditioningProfile ?? "" },
+                                        set: {
+                                            workflow.preconditioningProfile =
+                                                $0.isEmpty ? nil : $0
+                                        }))
+                                .textFieldStyle(.roundedBorder)
+                                .accessibilityIdentifier("targenPrecondProfile")
+                            Button("…") { workflow.browseForPreconditioningProfile() }
+                                .accessibilityIdentifier("btnBrowsePrecondProfile")
+                        }
+                        Toggle("OFPS high quality (-G)", isOn: $workflow.highQuality)
+                            .accessibilityIdentifier("targenHighQuality")
+                        Picker("Full-spread algorithm", selection: $workflow.algorithm) {
+                            ForEach(FullSpreadAlgorithm.allCases, id: \.self) {
+                                Text($0.displayName).tag($0)
+                            }
+                        }
+                        .accessibilityIdentifier("targenAlgorithm")
+                        if workflow.colourSpace == .cmyk {
+                            optionalInt("Total ink limit (-l)",
+                                        enabled: $workflow.inkLimitEnabled,
+                                        value: $workflow.totalInkLimit)
+                            .accessibilityElement(children: .contain)
+                            .accessibilityIdentifier("targenInkLimitGroup")
+                        }
+                        optionalDouble("Dark emphasis (-V)",
+                                       enabled: $workflow.darkEmphasisEnabled,
+                                       value: $workflow.darkEmphasis,
+                                       range: 0.0...3.0)
+                        .accessibilityIdentifier("targenDarkEmphasis")
+                        optionalDouble("Device power (-p)",
+                                       enabled: $workflow.devicePowerEnabled,
+                                       value: $workflow.devicePower,
+                                       range: 0.0...3.0)
+                        .accessibilityIdentifier("targenDevicePower")
+                    }
+                }
+            }
+            .foregroundStyle(Theme.text)
+            .padding(.top, 8)
+        }
+        .foregroundStyle(Theme.text)
+        .accessibilityElement(children: .contain)
+        .accessibilityIdentifier("targenAdvancedDetails")
+    }
+
+    private func optionalInt(
+        _ title: String,
+        enabled: Binding<Bool>,
+        value: Binding<Int>
+    ) -> some View {
+        HStack {
+            Toggle(title, isOn: enabled)
+                .toggleStyle(.checkbox)
+            if enabled.wrappedValue {
+                TextField("", value: value, format: .number)
+                    .textFieldStyle(.roundedBorder)
+                    .frame(width: 70)
+            }
+        }
+    }
+
+    private func optionalDouble(
+        _ title: String,
+        enabled: Binding<Bool>,
+        value: Binding<Double>,
+        range: ClosedRange<Double>
+    ) -> some View {
+        VStack(alignment: .leading) {
+            Toggle(title, isOn: enabled)
+                .toggleStyle(.checkbox)
+            if enabled.wrappedValue {
+                HStack {
+                    Slider(value: value, in: range)
+                    Text(value.wrappedValue, format: .number.precision(.fractionLength(2)))
+                        .frame(width: 44)
+                        .monospacedDigit()
+                }
+            }
+        }
+    }
+
+    // MARK: - Actions + log
+
+    private var actionRow: some View {
+        HStack {
+            Button(action: workflow.generateTarget) {
+                Label(workflow.targenRunning ? "Generating…" : "Generate Target",
+                      systemImage: "square.grid.3x3")
+            }
+            .controlSize(.large)
+            .disabled(!workflow.canGenerate || workflow.targenRunning)
+            .accessibilityIdentifier("btnGenerate")
+            if workflow.targenRunning {
+                ProgressView().controlSize(.small)
+            }
+            Spacer()
+        }
+    }
+
+    private var logSection: some View {
+        DisclosureGroup("Process log") {
+            ScrollView {
+                Text(workflow.targenLog.joined(separator: "\n"))
+                    .font(.system(.caption, design: .monospaced))
+                    .foregroundStyle(Theme.text)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .textSelection(.enabled)
+            }
+            .frame(minHeight: 120, maxHeight: 200)
+            .accessibilityIdentifier("targenLog")
+        }
+        .foregroundStyle(Theme.text)
+        .accessibilityElement(children: .contain)
+        .accessibilityIdentifier("targenLogContainer")
+    }
+}
diff --git a/Sources/ICCery/Stage2View.swift b/Sources/ICCery/Stage2View.swift
new file mode 100644
index 0000000..206fbf9
--- /dev/null
+++ b/Sources/ICCery/Stage2View.swift
@@ -0,0 +1,282 @@
+import SwiftUI
+import ICCeryCore
+
+/// Stage 2 — `#stage-2` Lay Out & Print (`printtarg` → `.ti2` + TIFFs,
+/// issues #9/#10, docs/09). Print controls are visible but inert —
+/// real spooling lands in M3.
+struct Stage2View: View {
+    @Bindable var workflow: TargetWorkflowViewModel
+
+    var body: some View {
+        ScrollView {
+            VStack(alignment: .leading, spacing: 16) {
+                cmWarning
+                formSection
+                labelSection
+                actionRow
+                logSection
+                gallerySection
+                printPanel
+            }
+            .padding(20)
+            .frame(maxWidth: .infinity, alignment: .leading)
+        }
+        .background(Theme.background)
+        .accessibilityIdentifier("stage-2")
+    }
+
+    // MARK: - Colour-management warning (#cmWarningBanner)
+
+    private var cmWarning: some View {
+        HStack(spacing: 10) {
+            Image(systemName: "exclamationmark.triangle.fill")
+                .foregroundStyle(.orange)
+            Text("Set your printer driver to “No Colour Adjustment” " +
+                 "(Epson) / “Off (No Colour Adjustment)” (Canon) before printing. " +
+                 "Any driver colour management corrupts the target.")
+                .font(.callout)
+                .foregroundStyle(Theme.text)
+            Spacer()
+        }
+        .padding(10)
+        .background(Color.orange.opacity(0.12))
+        .clipShape(RoundedRectangle(cornerRadius: Theme.Metrics.cornerMedium))
+        .overlay(
+            RoundedRectangle(cornerRadius: Theme.Metrics.cornerMedium)
+                .stroke(Color.orange.opacity(0.4))
+        )
+        .accessibilityIdentifier("cmWarningBanner")
+    }
+
+    // MARK: - Layout form
+
+    private var formSection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            HStack(spacing: 16) {
+                Picker("Instrument", selection: $workflow.instrument) {
+                    ForEach(PrintInstrument.allCases, id: \.self) {
+                        Text($0.displayName).tag($0)
+                    }
+                }
+                .accessibilityIdentifier("instrumentSelect")
+                Picker("Page size", selection: $workflow.pageSize) {
+                    ForEach(PageSize.allCases, id: \.self) {
+                        Text($0.rawValue).tag($0)
+                    }
+                }
+                .accessibilityIdentifier("pageSizeSelect")
+            }
+            if workflow.pageSize == .custom {
+                HStack(spacing: 8) {
+                    Text("Custom size (mm):")
+                    TextField("W", value: $workflow.customPageW, format: .number)
+                        .textFieldStyle(.roundedBorder).frame(width: 70)
+                        .accessibilityIdentifier("customPageW")
+                    Text("×")
+                    TextField("H", value: $workflow.customPageH, format: .number)
+                        .textFieldStyle(.roundedBorder).frame(width: 70)
+                        .accessibilityIdentifier("customPageH")
+                }
+                .accessibilityElement(children: .contain)
+                .accessibilityIdentifier("customPageSizeRow")
+            }
+            HStack(spacing: 16) {
+                Picker("Bit depth", selection: $workflow.bitDepth) {
+                    Text("8-bit TIFF").tag(TiffBitDepth.eight)
+                    Text("16-bit TIFF").tag(TiffBitDepth.sixteen)
+                }
+                Stepper("DPI: \(workflow.tiffDpi)",
+                        value: $workflow.tiffDpi, in: 72...600, step: 1)
+                    .accessibilityIdentifier("tiffDpi")
+            }
+            HStack(spacing: 16) {
+                Picker("Layout order", selection: $workflow.layoutOrder) {
+                    ForEach(LayoutOrder.allCases, id: \.self) {
+                        Text($0.displayName).tag($0)
+                    }
+                }
+                .accessibilityIdentifier("printtargLayoutOrder")
+                if workflow.layoutOrder == .customSeed {
+                    HStack {
+                        Text("Seed:")
+                        TextField("", value: $workflow.customSeed, format: .number)
+                            .textFieldStyle(.roundedBorder).frame(width: 80)
+                            .accessibilityIdentifier("printtargCustomSeed")
+                    }
+                    .accessibilityElement(children: .contain)
+                    .accessibilityIdentifier("printtargCustomSeedGroup")
+                }
+            }
+        }
+        .foregroundStyle(Theme.text)
+    }
+
+    // MARK: - Label (#btnToggleLabelEdit / #targetLabelPreview)
+
+    private var labelSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            HStack {
+                Text("Chart label").font(.headline).foregroundStyle(Theme.text)
+                Spacer()
+                Button(workflow.labelIsCustom ? "Use automatic label" : "Edit label…") {
+                    workflow.labelIsCustom.toggle()
+                }
+                .accessibilityIdentifier("btnToggleLabelEdit")
+            }
+            HStack(spacing: 12) {
+                TextField("Printer", text: $workflow.metaPrinter)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("targetMetadataPrinter")
+                TextField("Ink set", text: $workflow.metaInkSet)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("targetMetadataInkSet")
+            }
+            HStack(spacing: 12) {
+                TextField("Driver paper", text: $workflow.metaDriverPaper)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("targetMetadataDriverPaper")
+                TextField("Actual paper", text: $workflow.metaActualPaper)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("targetMetadataActualPaper")
+            }
+            if workflow.labelIsCustom {
+                TextField("Custom label", text: $workflow.customLabel)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("targetLabelPreview")
+            } else {
+                Text(workflow.automaticLabel)
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+                    .accessibilityIdentifier("targetLabelPreview")
+            }
+        }
+    }
+
+    // MARK: - Actions + log
+
+    private var actionRow: some View {
+        HStack {
+            Button(action: workflow.createLayout) {
+                Label(workflow.printtargRunning ? "Creating layout…" : "Create Layout",
+                      systemImage: "rectangle.grid.2x2")
+            }
+            .controlSize(.large)
+            .disabled(workflow.printtargRunning || workflow.wizard.basename.isEmpty)
+            .accessibilityIdentifier("btnCreateLayout")
+            if workflow.printtargRunning {
+                ProgressView().controlSize(.small)
+            }
+            Spacer()
+        }
+    }
+
+    private var logSection: some View {
+        DisclosureGroup("Process log") {
+            ScrollView {
+                Text(workflow.printtargLog.joined(separator: "\n"))
+                    .font(.system(.caption, design: .monospaced))
+                    .foregroundStyle(Theme.text)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .textSelection(.enabled)
+            }
+            .frame(minHeight: 100, maxHeight: 180)
+            .accessibilityIdentifier("printtargLog")
+        }
+        .foregroundStyle(Theme.text)
+        .accessibilityElement(children: .contain)
+        .accessibilityIdentifier("printtargLogContainer")
+    }
+
+    // MARK: - TIFF gallery (#tiffGallery) — host-side PNG only (#58)
+
+    @ViewBuilder
+    private var gallerySection: some View {
+        if let result = workflow.printtargResult {
+            VStack(alignment: .leading, spacing: 8) {
+                Text("Target pages — \(result.manifest.pages.count) page(s), " +
+                     "\(result.manifest.pages.reduce(0) { $0 + $1.patches }) patches")
+                    .font(.headline).foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("galleryInfo")
+                LazyVGrid(
+                    columns: [GridItem(.adaptive(minimum: 220))],
+                    spacing: 12
+                ) {
+                    ForEach(result.pages) { page in
+                        GalleryPageView(page: page)
+                    }
+                }
+                .accessibilityElement(children: .contain)
+                .accessibilityIdentifier("galleryGrid")
+            }
+            .accessibilityElement(children: .contain)
+            .accessibilityIdentifier("tiffGallery")
+        }
+    }
+
+    // MARK: - Raw print panel (#rawPrintPanel) — stubbed until M3
+
+    private var printPanel: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            Text("Print").font(.headline).foregroundStyle(Theme.text)
+            Text("Unmanaged printing (lp) lands in Milestone 3.")
+                .font(.caption).foregroundStyle(.secondary)
+                .accessibilityIdentifier("printNotification")
+            HStack(spacing: 8) {
+                Button("Print All") {}
+                    .accessibilityIdentifier("btnPrintAll")
+                    .disabled(true)
+                Button("Refresh Printers") {}
+                    .accessibilityIdentifier("btnRefreshPrinters")
+                    .disabled(true)
+                Button("Printer Properties") {}
+                    .accessibilityIdentifier("btnPrinterProperties")
+                    .disabled(true)
+                Spacer()
+                Button("Advance to Stage 3") { workflow.advanceToStage3() }
+                    .accessibilityIdentifier("btnAdvanceToStage3")
+                    .disabled(workflow.printtargResult == nil
+                              || !workflow.wizard.isUnlocked(.measure))
+            }
+        }
+        .padding(12)
+        .background(Theme.panel)
+        .clipShape(RoundedRectangle(cornerRadius: Theme.Metrics.cornerMedium))
+        .accessibilityElement(children: .contain)
+        .accessibilityIdentifier("rawPrintPanel")
+    }
+}
+
+/// One gallery cell: PNG preview + per-page stubbed Print button.
+private struct GalleryPageView: View {
+    let page: GalleryPage
+
+    var body: some View {
+        VStack(spacing: 6) {
+            if let png = page.previewPNG, let image = NSImage(data: png) {
+                Image(nsImage: image)
+                    .resizable()
+                    .scaledToFit()
+                    .frame(maxHeight: 240)
+            } else {
+                ZStack {
+                    Rectangle().fill(Theme.panel).frame(height: 160)
+                    Text(page.previewError ?? "No preview")
+                        .font(.caption).foregroundStyle(.secondary)
+                }
+            }
+            Text(page.page.filename)
+                .font(.caption).foregroundStyle(Theme.text)
+            Text("\(page.page.patches) patches · " +
+                 "\(Int(page.page.widthMm))×\(Int(page.page.heightMm)) mm")
+                .font(.caption2).foregroundStyle(.secondary)
+            Button("Print") {}
+                .disabled(true)
+                .accessibilityIdentifier("btnPrintPage-\(page.index)")
+        }
+        .padding(8)
+        .background(Theme.panel)
+        .clipShape(RoundedRectangle(cornerRadius: Theme.Metrics.cornerMedium))
+        .accessibilityElement(children: .contain)
+        .accessibilityIdentifier("galleryPage-\(page.index)")
+    }
+}
diff --git a/Sources/ICCery/TargetWorkflowViewModel.swift b/Sources/ICCery/TargetWorkflowViewModel.swift
new file mode 100644
index 0000000..80b5707
--- /dev/null
+++ b/Sources/ICCery/TargetWorkflowViewModel.swift
@@ -0,0 +1,465 @@
+import Foundation
+import Observation
+import ICCeryCore
+
+/// Stage 1/2 form state, runner orchestration, resume flow, and preset
+/// application (issues #7–#11).
+///
+/// `wizard` stays authoritative for persisted identity + disk gating;
+/// this model owns the editable form, logs, gallery, and preset state.
+/// All process work runs through `ArgyllRunner` off `@MainActor`; only
+/// coalesced log batches and completion hop back.
+@MainActor
+@Observable
+final class TargetWorkflowViewModel {
+
+    let wizard: WizardViewModel
+    let environment: AppEnvironment
+    private let fileDialogs = FileDialogService.shared
+
+    // MARK: - Stage 1 form (targen)
+
+    var colourSpace: ColourSpace = .rgb {
+        didSet {
+            guard colourSpace != oldValue else { return }
+            // CMYK black patches default to 0, RGB to 4 (docs/08).
+            blackPatches = colourSpace == .cmyk ? 0 : 4
+        }
+    }
+    var patchPreset: PatchCountPreset = .standard800
+    /// `#patchCountCustom` — used when `patchPreset == .custom`.
+    var customPatchCount = 2500
+    var whitePatches = 4
+    var blackPatches = 4
+
+    // Advanced — each optional flag is enabled + value, so an untouched
+    // control emits nothing (#advanced fields are opt-in).
+    var greyStepsEnabled = false
+    var greySteps = 5
+    var singleChannelEnabled = false
+    var singleChannelSteps = 5
+    var neutralStepsEnabled = false
+    var neutralSteps = 3
+    var neutralConcEnabled = false
+    var neutralConcentration = 0.50
+    var preconditioningProfile: String?
+    var highQuality = false
+    var adaptationEnabled = false
+    var adaptation = 0.10
+    var algorithm: FullSpreadAlgorithm = .ofps
+    var inkLimitEnabled = false
+    var totalInkLimit = 320
+    var darkEmphasisEnabled = false
+    var darkEmphasis = 1.0
+    var devicePowerEnabled = false
+    var devicePower = 1.0
+
+    /// `#targetBasename` — no placeholder is ever invented (#60).
+    var targetBasename = ""
+    /// `#selectedPathDisplay` / resolved cwd.
+    var targetDirectory: URL?
+
+    // MARK: - Stage 2 form (printtarg)
+
+    var instrument: PrintInstrument = .i1
+    var pageSize: PageSize = .a4
+    var customPageW = 210.0
+    var customPageH = 297.0
+    var bitDepth: TiffBitDepth = .eight
+    /// `#tiffDpi` — two-way bound; presets can change it (150-DPI draft
+    /// regression must be visible here).
+    var tiffDpi = 300
+    var layoutOrder: LayoutOrder = .deterministic
+    var customSeed = 1
+    var labelIsCustom = false
+    var customLabel = ""
+    var metaPrinter = ""
+    var metaInkSet = ""
+    var metaDriverPaper = ""
+    var metaActualPaper = ""
+
+    // MARK: - Run state
+
+    var targenRunning = false
+    var targenLog: [String] = []
+    var printtargRunning = false
+    var printtargLog: [String] = []
+    var printtargResult: PrinttargResult?
+    /// Sticky until the target changes: `.ti2` resume landed us on
+    /// Stage 3 (`#stage3LoadedTargetBanner` data).
+    var resumedFromTi2 = false
+
+    // MARK: - Presets
+
+    var presets: [ProfilingPreset] = []
+    var selectedPresetID = "none"
+    var showingSavePreset = false
+    var showingManagePresets = false
+    var savePresetName = ""
+    var savePresetDesc = ""
+
+    init(environment: AppEnvironment = .live()) {
+        self.environment = environment
+        self.wizard = WizardViewModel(stateStore: environment.stateStore)
+        reloadPresets()
+    }
+
+    // MARK: - Derived
+
+    var effectivePatchCount: Int {
+        patchPreset.patchCount ?? customPatchCount
+    }
+
+    var canGenerate: Bool {
+        PathSecurity.isValidBasename(targetBasename) && targetDirectory != nil
+    }
+
+    var labelMetadata: TargetLabelMetadata {
+        TargetLabelMetadata(
+            printer: metaPrinter, inkSet: metaInkSet,
+            driverPaper: metaDriverPaper, actualPaper: metaActualPaper)
+    }
+
+    /// `#targetLabelPreview` — live preview of the automatic label.
+    var automaticLabel: String {
+        PrinttargLabel.automatic(
+            basename: wizard.basename.isEmpty ? "target" : wizard.basename,
+            metadata: labelMetadata)
+    }
+
+    var selectedPreset: ProfilingPreset? {
+        presets.first { $0.id == selectedPresetID }
+    }
+
+    // MARK: - Stage 1: generate
+
+    func buildTargenConfig() -> TargenConfig {
+        TargenConfig(
+            colourSpace: colourSpace,
+            patchCount: effectivePatchCount,
+            whitePatches: whitePatches,
+            blackPatches: blackPatches,
+            greySteps: greyStepsEnabled ? greySteps : nil,
+            singleChannelSteps: singleChannelEnabled ? singleChannelSteps : nil,
+            neutralSteps: neutralStepsEnabled ? neutralSteps : nil,
+            neutralConcentration: neutralConcEnabled ? neutralConcentration : nil,
+            preconditioningProfile: preconditioningProfile,
+            ofpsHighQuality: highQuality ? true : nil,
+            ofpsAdaptation: adaptationEnabled ? adaptation : nil,
+            fullSpreadAlgorithm: algorithm == .ofps ? nil : algorithm,
+            totalInkLimit: inkLimitEnabled ? totalInkLimit : nil,
+            darkEmphasis: darkEmphasisEnabled ? darkEmphasis : nil,
+            devicePower: devicePowerEnabled ? devicePower : nil,
+            basename: targetBasename,
+            workingDirectory: targetDirectory
+        )
+    }
+
+    func browseForTargetFile() {
+        let url = UITestHooks.isEnabled
+            ? UITestHooks.saveTargetURL
+            : fileDialogs.selectTargetFile()
+        guard let url else { return }
+        targetBasename = url.deletingPathExtension().lastPathComponent
+        targetDirectory = url.deletingLastPathComponent()
+    }
+
+    func browseForWorkingDirectory() {
+        let url = UITestHooks.isEnabled
+            ? UITestHooks.workDirURL
+            : fileDialogs.selectDirectory()
+        if let url { targetDirectory = url }
+    }
+
+    func browseForPreconditioningProfile() {
+        if let url = fileDialogs.selectProfileFile() {
+            preconditioningProfile = url.path
+        }
+    }
+
+    func generateTarget() {
+        guard canGenerate, !targenRunning else { return }
+        let config = buildTargenConfig()
+        targenRunning = true
+        targenLog = []
+        resumedFromTi2 = false
+        let runner = environment.runner
+        Task {
+            do {
+                let url = try await runner.runTargen(config: config) { [weak self] batch in
+                    Task { @MainActor [weak self] in
+                        self?.targenLog.append(contentsOf: batch)
+                    }
+                }
+                wizard.setTarget(
+                    basename: config.basename,
+                    workingDirectory: config.workingDirectory)
+                wizard.refreshGating()
+                wizard.showNotice("Target generated: \(url.lastPathComponent)")
+                wizard.go(to: .layOutPrint)
+            } catch {
+                wizard.showNotice(
+                    "targen failed: \(error.localizedDescription)", kind: .error)
+            }
+            targenRunning = false
+        }
+    }
+
+    // MARK: - Issue 8: resume an existing target
+
+    /// `#btnOpenExisting` — open `.ti1`/`.ti2` (open dialog, #103).
+    /// `.ti1` → Stage 2; `.ti2` → Stage 3 with the resume notice, but
+    /// only when the sibling `.ti1` exists so the artefact gate holds.
+    func openExistingTarget() {
+        let url = UITestHooks.isEnabled
+            ? UITestHooks.existingTargetURL
+            : fileDialogs.selectExistingTarget()
+        guard let url else { return }
+
+        let stem = url.deletingPathExtension().lastPathComponent
+        let dir = url.deletingLastPathComponent()
+        guard PathSecurity.isValidBasename(stem) else {
+            wizard.showNotice("Invalid target name.", kind: .error)
+            return
+        }
+
+        switch url.pathExtension.lowercased() {
+        case "ti1":
+            wizard.setTarget(basename: stem, workingDirectory: dir)
+            wizard.refreshGating()
+            resumedFromTi2 = false
+            wizard.go(to: .layOutPrint)
+        case "ti2":
+            let header = Ti2Header.parse(url)
+            guard header.hasSiblingTi1 else {
+                wizard.showNotice(
+                    "Cannot resume \(stem).ti2 — the sibling \(stem).ti1 is missing.",
+                    kind: .error)
+                return
+            }
+            wizard.setTarget(basename: stem, workingDirectory: dir)
+            wizard.refreshGating()
+            resumedFromTi2 = true
+            wizard.showNotice("Resumed from .ti2", kind: .info, autoHideAfter: nil)
+            wizard.go(to: .measure)
+        default:
+            wizard.showNotice(
+                "Not a target file — choose a .ti1 or .ti2.", kind: .error)
+        }
+    }
+
+    // MARK: - Stage 2: create layout
+
+    func buildPrinttargConfig() -> PrinttargConfig {
+        PrinttargConfig(
+            instrument: instrument,
+            pageSize: pageSize,
+            customPageWidth: customPageW,
+            customPageHeight: customPageH,
+            bitDepth: bitDepth,
+            dpi: tiffDpi,
+            layoutOrder: layoutOrder,
+            customSeed: customSeed,
+            label: PrinttargLabel.resolved(
+                customLabel: labelIsCustom ? customLabel : nil,
+                basename: wizard.basename,
+                metadata: labelMetadata),
+            basename: wizard.basename,
+            workingDirectory: wizard.effectiveWorkingDirectory
+        )
+    }
+
+    func createLayout() {
+        guard wizard.isUnlocked(.layOutPrint), !printtargRunning else { return }
+        let config = buildPrinttargConfig()
+        printtargRunning = true
+        printtargLog = []
+        printtargResult = nil
+        let runner = environment.runner
+        Task {
+            do {
+                let result = try await runner.runPrinttarg(config: config) { [weak self] batch in
+                    Task { @MainActor [weak self] in
+                        self?.printtargLog.append(contentsOf: batch)
+                    }
+                }
+                printtargResult = result
+                wizard.refreshGating()
+                wizard.showNotice(
+                    "Layout created — \(result.manifest.pages.count) page(s) ready.")
+            } catch {
+                // Stay on Stage 2: non-zero exit, malformed manifest, or
+                // missing .ti2 must never advance the wizard (#156).
+                wizard.showNotice(
+                    "printtarg failed: \(error.localizedDescription)", kind: .error)
+            }
+            printtargRunning = false
+        }
+    }
+
+    /// `#btnAdvanceToStage3` — manual advance once `.ti2` exists.
+    func advanceToStage3() {
+        wizard.refreshGating()
+        wizard.go(to: .measure)
+    }
+
+    // MARK: - Presets
+
+    func reloadPresets() {
+        presets = environment.presetStore.all()
+    }
+
+    /// Applies every Stage 1/2 field of the preset to the live form
+    /// (bidirectional — the draft preset's dpi=150 must be visible).
+    func applyPreset(_ preset: ProfilingPreset) {
+        colourSpace = preset.colourSpace == "cmyk" ? .cmyk : .rgb
+        patchPreset = PatchCountPreset(rawValue: "\(preset.patchCount)") ?? .custom
+        customPatchCount = preset.patchCount
+        whitePatches = preset.whitePatches
+        blackPatches = preset.blackPatches
+        greySteps = preset.greySteps ?? 5; greyStepsEnabled = preset.greySteps != nil
+        singleChannelSteps = preset.singleChannelSteps ?? 5
+        singleChannelEnabled = preset.singleChannelSteps != nil
+        neutralSteps = preset.neutralSteps ?? 3
+        neutralStepsEnabled = preset.neutralSteps != nil
+        neutralConcentration = preset.neutralConcentration ?? 0.50
+        neutralConcEnabled = preset.neutralConcentration != nil
+        preconditioningProfile = preset.preconditioningProfile
+        highQuality = preset.ofpsHighQuality == true
+        adaptation = preset.ofpsAdaptation ?? 0.10
+        adaptationEnabled = preset.ofpsAdaptation != nil
+        algorithm = preset.fullSpreadAlgorithm
+            .flatMap { FullSpreadAlgorithm(presetValue: $0) } ?? .ofps
+        totalInkLimit = preset.totalInkLimit ?? 320
+        inkLimitEnabled = preset.totalInkLimit != nil
+        darkEmphasis = preset.darkEmphasis ?? 1.0
+        darkEmphasisEnabled = preset.darkEmphasis != nil
+        devicePower = preset.devicePower ?? 1.0
+        devicePowerEnabled = preset.devicePower != nil
+
+        instrument = PrintInstrument(rawValue: preset.instrument) ?? .i1
+        if let size = PageSize(rawValue: preset.pageSize) {
+            pageSize = size
+        } else if let (w, h) = Self.parseCustomPage(preset.pageSize) {
+            pageSize = .custom; customPageW = w; customPageH = h
+        } else {
+            pageSize = .a4
+        }
+        bitDepth = preset.bitDepth == 16 ? .sixteen : .eight
+        tiffDpi = preset.dpi
+        if preset.noRandomize == true {
+            layoutOrder = .raster
+        } else if (preset.randomSeed ?? 1) == 1 {
+            layoutOrder = .deterministic
+        } else {
+            layoutOrder = .customSeed
+        }
+        customSeed = preset.randomSeed ?? 1
+
+        selectedPresetID = preset.id
+    }
+
+    /// Snapshot of the live Stage 1/2 form as a custom preset.
+    func saveCurrentAsPreset() {
+        let name = savePresetName.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !name.isEmpty else {
+            wizard.showNotice("Preset needs a name.", kind: .warning)
+            return
+        }
+        let preset = ProfilingPreset(
+            id: "custom-\(UUID().uuidString.lowercased())",
+            name: name,
+            description: savePresetDesc.trimmingCharacters(in: .whitespacesAndNewlines),
+            colourSpace: colourSpace == .cmyk ? "cmyk" : "rgb",
+            patchCount: effectivePatchCount,
+            whitePatches: whitePatches,
+            blackPatches: blackPatches,
+            greySteps: greyStepsEnabled ? greySteps : nil,
+            singleChannelSteps: singleChannelEnabled ? singleChannelSteps : nil,
+            neutralSteps: neutralStepsEnabled ? neutralSteps : nil,
+            neutralConcentration: neutralConcEnabled ? neutralConcentration : nil,
+            preconditioningProfile: preconditioningProfile,
+            ofpsHighQuality: highQuality ? true : nil,
+            ofpsAdaptation: adaptationEnabled ? adaptation : nil,
+            fullSpreadAlgorithm: algorithm.presetValue,
+            totalInkLimit: inkLimitEnabled ? totalInkLimit : nil,
+            darkEmphasis: darkEmphasisEnabled ? darkEmphasis : nil,
+            devicePower: devicePowerEnabled ? devicePower : nil,
+            instrument: instrument.rawValue,
+            pageSize: pageSize == .custom
+                ? "\(Int(customPageW))x\(Int(customPageH))"
+                : pageSize.rawValue,
+            bitDepth: bitDepth.rawValue,
+            dpi: tiffDpi,
+            randomSeed: layoutOrder == .deterministic ? 1 : customSeed,
+            noRandomize: layoutOrder == .raster
+        )
+        do {
+            try environment.presetStore.saveCustom(preset)
+            reloadPresets()
+            selectedPresetID = preset.id
+            showingSavePreset = false
+            savePresetName = ""
+            savePresetDesc = ""
+            wizard.showNotice("Preset saved: \(preset.name)")
+        } catch {
+            wizard.showNotice(
+                "Could not save preset: \(error.localizedDescription)", kind: .error)
+        }
+    }
+
+    func deletePreset(_ preset: ProfilingPreset) {
+        do {
+            if try environment.presetStore.deleteCustom(id: preset.id) {
+                if selectedPresetID == preset.id { selectedPresetID = "none" }
+                reloadPresets()
+            } else {
+                wizard.showNotice("Built-in presets cannot be deleted.", kind: .warning)
+            }
+        } catch {
+            wizard.showNotice(
+                "Could not delete preset: \(error.localizedDescription)", kind: .error)
+        }
+    }
+
+    func importPreset() {
+        let url = UITestHooks.isEnabled
+            ? UITestHooks.presetImportURL
+            : fileDialogs.selectPresetFile()
+        guard let url else { return }
+        do {
+            let data = try Data(contentsOf: url)
+            let preset = try environment.presetStore.import(data)
+            try environment.presetStore.saveCustom(preset)
+            reloadPresets()
+            selectedPresetID = preset.id
+            wizard.showNotice("Preset imported: \(preset.name)")
+        } catch {
+            wizard.showNotice(
+                "Import failed: \(error.localizedDescription)", kind: .error)
+        }
+    }
+
+    func exportPreset(_ preset: ProfilingPreset) {
+        let url = UITestHooks.isEnabled
+            ? UITestHooks.presetExportURL
+            : fileDialogs.selectPresetSavePath(name: preset.id)
+        guard let url else { return }
+        do {
+            try environment.presetStore.export(preset)
+                .write(to: url, options: .atomic)
+            wizard.showNotice("Preset exported: \(url.lastPathComponent)")
+        } catch {
+            wizard.showNotice(
+                "Export failed: \(error.localizedDescription)", kind: .error)
+        }
+    }
+
+    static func parseCustomPage(_ raw: String) -> (Double, Double)? {
+        let parts = raw.lowercased().split(separator: "x")
+        guard parts.count == 2,
+              let w = Double(parts[0]), let h = Double(parts[1]),
+              w >= 50, h >= 50 else { return nil }
+        return (w, h)
+    }
+}
diff --git a/Tests/ICCeryCoreTests/PresetTests.swift b/Tests/ICCeryCoreTests/PresetTests.swift
new file mode 100644
index 0000000..0e8c519
--- /dev/null
+++ b/Tests/ICCeryCoreTests/PresetTests.swift
@@ -0,0 +1,232 @@
+import Testing
+import Foundation
+@testable import ICCeryCore
+
+@Suite("ProfilingPreset")
+struct ProfilingPresetTests {
+
+    @Test("snake_case keys round-trip through Codable")
+    func roundTrip() throws {
+        var p = PresetCatalog.highQualityCMYK
+        p.colprofInputViewingCond = "D50_2"
+        let data = try JSONEncoder().encode(p)
+        let decoded = try JSONDecoder().decode(ProfilingPreset.self, from: data)
+        #expect(decoded == p)
+        // Spot-check the wire format.
+        let obj = try JSONSerialization.jsonObject(with: data) as! [String: Any]
+        #expect(obj["colour_space"] as? String == "cmyk")
+        #expect(obj["patch_count"] as? Int == 1500)
+        #expect(obj["total_ink_limit"] as? Int == 320)
+        #expect(obj["bit_depth"] as? Int == 16)
+        #expect(obj["colprof_input_viewing_cond"] as? String == "D50_2")
+    }
+
+    @Test("Unknown keys ignored; missing required field fails")
+    func schemaTolerance() throws {
+        let json = """
+        {"id":"x","name":"N","colour_space":"rgb","patch_count":10,
+         "white_patches":1,"black_patches":1,"instrument":"i1",
+         "page_size":"A4","bit_depth":8,"dpi":300,"future_key":42}
+        """.data(using: .utf8)!
+        let ok = try JSONDecoder().decode(ProfilingPreset.self, from: json)
+        #expect(ok.id == "x")
+
+        let missing = """
+        {"id":"x","name":"N","colour_space":"rgb"}
+        """.data(using: .utf8)!
+        #expect(throws: DecodingError.self) {
+            try JSONDecoder().decode(ProfilingPreset.self, from: missing)
+        }
+    }
+
+    @Test("Validation rejects bad colour space / dpi / bit depth")
+    func validation() {
+        #expect(throws: ProfilingPreset.ValidationError.self) {
+            try ProfilingPreset(id: "a", name: "n", colourSpace: "lab").validated()
+        }
+        #expect(throws: ProfilingPreset.ValidationError.self) {
+            try ProfilingPreset(id: "a", name: "n", dpi: 10).validated()
+        }
+        #expect(throws: ProfilingPreset.ValidationError.self) {
+            try ProfilingPreset(id: "a", name: "n", bitDepth: 12).validated()
+        }
+        #expect(throws: ProfilingPreset.ValidationError.self) {
+            try ProfilingPreset(id: "a", name: "n", patchCount: 0).validated()
+        }
+    }
+}
+
+@Suite("PresetCatalog")
+struct PresetCatalogTests {
+
+    @Test("Four built-ins with the documented values")
+    func builtIns() {
+        #expect(PresetCatalog.builtIns.count == 4)
+        let byID = Dictionary(uniqueKeysWithValues: PresetCatalog.builtIns.map { ($0.id, $0) })
+
+        let std = byID["preset-std-rgb"]!
+        #expect(std.colourSpace == "rgb" && std.patchCount == 800
+                && std.pageSize == "A4" && std.bitDepth == 8
+                && std.dpi == 300 && std.colprofQuality == "m"
+                && std.whitePatches == 4 && std.blackPatches == 4)
+
+        let hq = byID["preset-hq-cmyk"]!
+        #expect(hq.colourSpace == "cmyk" && hq.patchCount == 1500
+                && hq.pageSize == "A3" && hq.bitDepth == 16
+                && hq.dpi == 300 && hq.colprofQuality == "h"
+                && hq.totalInkLimit == 320 && hq.blackPatches == 8)
+
+        let draft = byID["preset-draft-rgb"]!
+        #expect(draft.colourSpace == "rgb" && draft.patchCount == 400
+                && draft.pageSize == "A4" && draft.bitDepth == 8
+                && draft.dpi == 150 && draft.colprofQuality == "l")
+
+        let ultra = byID["preset-ultra-rgb"]!
+        #expect(ultra.colourSpace == "rgb" && ultra.patchCount == 2500
+                && ultra.pageSize == "A3" && ultra.bitDepth == 16
+                && ultra.dpi == 300 && ultra.colprofQuality == "u"
+                && ultra.ofpsHighQuality == true
+                && ultra.whitePatches == 6 && ultra.blackPatches == 6)
+
+        for p in PresetCatalog.builtIns {
+            #expect(p.instrument == "i1")
+            #expect(p.colprofFwa == "D50")
+            #expect(p.randomSeed == 1)
+            #expect(p.noRandomize == false)
+            #expect(p.colprofAlgorithm == "l")
+        }
+    }
+
+    @Test("Custom presets overlay by id; built-ins are not deletable")
+    func overlay() {
+        let custom = ProfilingPreset(
+            id: "preset-std-rgb", name: "Shadowed", patchCount: 42)
+        let all = PresetCatalog.all(custom: [custom])
+        #expect(all.count == 4)
+        #expect(all.first { $0.id == "preset-std-rgb" }?.patchCount == 42)
+        #expect(PresetCatalog.isBuiltIn("preset-std-rgb"))
+        #expect(!PresetCatalog.isBuiltIn("custom-1"))
+    }
+}
+
+@Suite("PresetStore")
+struct PresetStoreTests {
+
+    private func tempSettingsURL() throws -> URL {
+        let dir = FileManager.default.temporaryDirectory
+            .appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+        return dir.appendingPathComponent("settings.json")
+    }
+
+    @Test("CRUD + export/import round-trip")
+    func crud() throws {
+        let url = try tempSettingsURL()
+        defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }
+        let store = PresetStore(settingsStore: SettingsStore(fileURL: url))
+
+        var p = ProfilingPreset(id: "custom-x", name: "Mine", patchCount: 999, dpi: 150)
+        try store.saveCustom(p)
+        #expect(store.customs().count == 1)
+        #expect(store.all().count == 5)
+
+        p.name = "Renamed"
+        try store.saveCustom(p)
+        #expect(store.customs().count == 1)
+        #expect(store.customs()[0].name == "Renamed")
+
+        let data = try store.export(p)
+        let imported = try store.import(data)
+        #expect(imported.name == "Renamed")
+        #expect(imported.dpi == 150)
+
+        #expect(try store.deleteCustom(id: "custom-x"))
+        #expect(store.customs().isEmpty)
+        #expect(try !store.deleteCustom(id: "preset-std-rgb"))
+    }
+
+    @Test("Import rewrites a built-in id to a fresh custom id")
+    func importBuiltinCollision() throws {
+        let url = try tempSettingsURL()
+        defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }
+        let store = PresetStore(settingsStore: SettingsStore(fileURL: url))
+        let data = try store.export(PresetCatalog.standardRGB)
+        let imported = try store.import(data)
+        #expect(imported.id.hasPrefix("custom-"))
+        #expect(!PresetCatalog.isBuiltIn(imported.id))
+    }
+
+    @Test("Built-ins are immutable through saveCustom")
+    func builtInImmutable() throws {
+        let url = try tempSettingsURL()
+        defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }
+        let store = PresetStore(settingsStore: SettingsStore(fileURL: url))
+        var shadowed = PresetCatalog.standardRGB
+        shadowed.name = "Hacked"
+        #expect(throws: PresetStore.PresetStoreError.self) {
+            try store.saveCustom(shadowed)
+        }
+    }
+}
+
+@Suite("AppSettings preset migration")
+struct PresetMigrationTests {
+
+    private func tempSettingsURL() throws -> URL {
+        let dir = FileManager.default.temporaryDirectory
+            .appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+        return dir.appendingPathComponent("settings.json")
+    }
+
+    @Test("Legacy M1 custom_presets migrate to typed schema")
+    func legacyMigration() throws {
+        let url = try tempSettingsURL()
+        defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }
+        let legacy = """
+        {"custom_presets":[
+            {"name":"Old One","values":{"colour_space":"cmyk","patch_count":"900",
+             "dpi":"150","bit_depth":"16","instrument":"p3","page_size":"A3"}},
+            {"name":"","values":{}},
+            42
+        ]}
+        """.data(using: .utf8)!
+        try legacy.write(to: url)
+
+        let settings = SettingsStore(fileURL: url).load()
+        #expect(settings.customPresets.count == 1)
+        let p = settings.customPresets[0]
+        #expect(p.name == "Old One")
+        #expect(p.id.hasPrefix("custom-0-"))
+        #expect(p.colourSpace == "cmyk")
+        #expect(p.patchCount == 900)
+        #expect(p.dpi == 150)
+        #expect(p.bitDepth == 16)
+        #expect(p.instrument == "p3")
+        #expect(p.pageSize == "A3")
+    }
+
+    @Test("Typed presets load and re-save as the typed schema")
+    func typedRoundTrip() throws {
+        let url = try tempSettingsURL()
+        defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }
+        let store = SettingsStore(fileURL: url)
+        var s = AppSettings()
+        s.customPresets = [ProfilingPreset(id: "c1", name: "C1", patchCount: 700)]
+        try store.save(s)
+        let loaded = store.load()
+        #expect(loaded.customPresets.first?.patchCount == 700)
+    }
+
+    @Test("Draft preset dpi=150 survives Codable + settings round-trip")
+    func draftDPI() throws {
+        let url = try tempSettingsURL()
+        defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }
+        let store = PresetStore(settingsStore: SettingsStore(fileURL: url))
+        let data = try store.export(PresetCatalog.draftRGB)
+        let obj = try JSONSerialization.jsonObject(with: data) as! [String: Any]
+        #expect(obj["dpi"] as? Int == 150)
+        let back = try store.import(data)
+        #expect(back.dpi == 150)
+    }
+}
diff --git a/Tests/ICCeryCoreTests/PrinttargTests.swift b/Tests/ICCeryCoreTests/PrinttargTests.swift
new file mode 100644
index 0000000..440b919
--- /dev/null
+++ b/Tests/ICCeryCoreTests/PrinttargTests.swift
@@ -0,0 +1,429 @@
+import Testing
+import Foundation
+@testable import ICCeryCore
+
+@Suite("PrinttargArgs")
+struct PrinttargArgsTests {
+
+    private func config(
+        instrument: PrintInstrument = .i1,
+        pageSize: PageSize = .a4,
+        customW: Double = 210, customH: Double = 297,
+        bitDepth: TiffBitDepth = .eight,
+        dpi: Int = 300,
+        layout: LayoutOrder = .deterministic,
+        seed: Int = 1,
+        label: String? = nil,
+        calFile: String? = nil,
+        calEmbed: Bool = false,
+        basename: String = "target"
+    ) -> PrinttargConfig {
+        PrinttargConfig(
+            instrument: instrument, pageSize: pageSize,
+            customPageWidth: customW, customPageHeight: customH,
+            bitDepth: bitDepth, dpi: dpi,
+            layoutOrder: layout, customSeed: seed, label: label,
+            calibrationFile: calFile, calibrationEmbedOnly: calEmbed,
+            basename: basename
+        )
+    }
+
+    @Test("Baseline: -v -u -i i1 -p A4 -R 1 -t 300")
+    func baseline() throws {
+        let args = try PrinttargArgs.build(config: config())
+        #expect(args == ["-v", "-u", "-i", "i1", "-p", "A4",
+                         "-R", "1", "-t", "300", "target"])
+    }
+
+    @Test("Default layout is deterministic -R 1, never bare")
+    func deterministicDefault() throws {
+        let args = try PrinttargArgs.build(config: config())
+        #expect(args.contains("-R"))
+        #expect(!args.contains("-r"))
+        #expect(args[args.firstIndex(of: "-R")! + 1] == "1")
+    }
+
+    @Test("Custom seed -R N; seed < 1 throws")
+    func customSeed() throws {
+        let args = try PrinttargArgs.build(config: config(layout: .customSeed, seed: 42))
+        #expect(args[args.firstIndex(of: "-R")! + 1] == "42")
+        #expect(throws: PrinttargArgError.self) {
+            try PrinttargArgs.build(config: config(layout: .customSeed, seed: 0))
+        }
+    }
+
+    @Test("Raster emits -r and supersedes seed (printtarg -r, not targen -r)")
+    func raster() throws {
+        let args = try PrinttargArgs.build(config: config(layout: .raster, seed: 9))
+        #expect(args.contains("-r"))
+        #expect(!args.contains("-R"))
+    }
+
+    @Test("Label: -d emits the resolved string, not a colour space")
+    func label() throws {
+        let args = try PrinttargArgs.build(
+            config: config(label: "ICCery - t - P - I - D - A - 01/02/2026 03:04"))
+        let i = args.firstIndex(of: "-d")!
+        #expect(args[i + 1].hasPrefix("ICCery - t"))
+    }
+
+    @Test("Bit depth: -t 8-bit, -T 16-bit; DPI range 72-600")
+    func bitDepthAndDPI() throws {
+        #expect(try PrinttargArgs.build(config: config(bitDepth: .sixteen, dpi: 600))
+            .contains("-T"))
+        #expect(try PrinttargArgs.build(config: config(bitDepth: .eight, dpi: 72))
+            .contains("-t"))
+        #expect(throws: PrinttargArgError.self) {
+            try PrinttargArgs.build(config: config(dpi: 71))
+        }
+        #expect(throws: PrinttargArgError.self) {
+            try PrinttargArgs.build(config: config(dpi: 601))
+        }
+    }
+
+    @Test("All instruments emit their Argyll code")
+    func instruments() throws {
+        let expected: [(PrintInstrument, String)] = [
+            (.i1, "i1"), (.p3, "p3"), (.cm, "CM"), (.ss, "SS"),
+            (.dtp20, "20"), (.dtp22, "22"), (.dtp41, "41"), (.dtp51, "51"),
+        ]
+        for (inst, code) in expected {
+            let args = try PrinttargArgs.build(config: config(instrument: inst))
+            #expect(args[args.firstIndex(of: "-i")! + 1] == code)
+        }
+    }
+
+    @Test("All fixed page sizes; custom emits WxH in mm")
+    func pageSizes() throws {
+        for size in PageSize.allCases where size != .custom {
+            let args = try PrinttargArgs.build(config: config(pageSize: size))
+            #expect(args[args.firstIndex(of: "-p")! + 1] == size.rawValue)
+        }
+        let custom = try PrinttargArgs.build(config: config(
+            pageSize: .custom, customW: 150, customH: 220))
+        #expect(custom[custom.firstIndex(of: "-p")! + 1] == "150x220")
+    }
+
+    @Test("Custom page below 50 mm throws")
+    func customPageTooSmall() {
+        #expect(throws: PrinttargArgError.self) {
+            try PrinttargArgs.build(config: config(pageSize: .custom, customW: 49.9))
+        }
+        #expect(throws: PrinttargArgError.self) {
+            try PrinttargArgs.build(config: config(pageSize: .custom, customH: 10))
+        }
+    }
+
+    @Test("Calibration: -K applies, -I embeds")
+    func calibrationFlags() throws {
+        let k = try PrinttargArgs.build(config: config(calFile: "/tmp/a.cal"))
+        #expect(k[k.firstIndex(of: "-K")! + 1] == "/tmp/a.cal")
+        let i = try PrinttargArgs.build(config: config(calFile: "/tmp/a.cal", calEmbed: true))
+        #expect(i[i.firstIndex(of: "-I")! + 1] == "/tmp/a.cal")
+        #expect(!i.contains("-K"))
+    }
+
+    @Test("CAL_ basename never gets -K or -I")
+    func calProtection() throws {
+        let args = try PrinttargArgs.build(
+            config: config(calFile: "/tmp/a.cal", basename: "CAL_test"))
+        #expect(!args.contains("-K"))
+        #expect(!args.contains("-I"))
+    }
+
+    @Test("Unsafe basename throws")
+    func unsafeBasename() {
+        #expect(throws: PathSecurity.Error.self) {
+            try PrinttargArgs.build(config: config(basename: "../x"))
+        }
+    }
+}
+
+@Suite("PrinttargLabel")
+struct PrinttargLabelTests {
+
+    private var fixedDate: Date {
+        var comps = DateComponents()
+        comps.year = 2026; comps.month = 2; comps.day = 3
+        comps.hour = 14; comps.minute = 5
+        return Calendar(identifier: .gregorian).date(from: comps)!
+    }
+
+    @Test("Automatic label: ICCery - basename - P - I - DP - AP - DD/MM/YYYY HH:MM")
+    func automatic() {
+        let label = PrinttargLabel.automatic(
+            basename: "tgt",
+            metadata: TargetLabelMetadata(
+                printer: "Epson", inkSet: "CMYK",
+                driverPaper: "Photo", actualPaper: "Matte"),
+            date: fixedDate, timeZone: .current)
+        #expect(label.hasPrefix("ICCery - tgt - Epson - CMYK - Photo - Matte - "))
+        #expect(label.hasSuffix("03/02/2026") || label.contains("/02/2026"))
+    }
+
+    @Test("Missing metadata becomes Unspecified")
+    func unspecified() {
+        let label = PrinttargLabel.automatic(
+            basename: "tgt", metadata: TargetLabelMetadata(),
+            date: fixedDate, timeZone: .current)
+        #expect(label.contains(" - Unspecified - Unspecified - Unspecified - Unspecified - "))
+    }
+
+    @Test("Manual label wins over automatic")
+    func manualWins() {
+        let resolved = PrinttargLabel.resolved(
+            customLabel: "  My Label  ", basename: "tgt",
+            metadata: TargetLabelMetadata(), date: fixedDate)
+        #expect(resolved == "My Label")
+    }
+}
+
+@Suite("PrinttargManifest")
+struct PrinttargManifestTests {
+
+    private let prettySingle = """
+        Some log line
+        Doing work...
+        {
+            "event": "manifest",
+            "pages": [
+                {
+                    "filename": "target.tif",
+                    "patches": 800,
+                    "width_mm": 210.0,
+                    "height_mm": 297.0
+                }
+            ]
+        }
+        trailing text
+        """
+
+    private let prettyMulti = """
+        {
+            "event": "manifest",
+            "pages": [
+                {"filename": "p1.tif", "patches": 400, "width_mm": 210, "height_mm": 148},
+                {"filename": "p2.tif", "patches": 400, "width_mm": 210, "height_mm": 148}
+            ]
+        }
+        """
+
+    @Test("Decodes a single-page pretty manifest amid log noise")
+    func singlePage() throws {
+        let m = try PrinttargManifestExtractor.manifest(from: prettySingle)
+        #expect(m.event == "manifest")
+        #expect(m.pages.count == 1)
+        #expect(m.pages[0].filename == "target.tif")
+        #expect(m.pages[0].patches == 800)
+    }
+
+    @Test("Multi-page manifest preserves order")
+    func multiPage() throws {
+        let m = try PrinttargManifestExtractor.manifest(from: prettyMulti)
+        #expect(m.pages.map(\.filename) == ["p1.tif", "p2.tif"])
+    }
+
+    @Test("No JSON document → noJSONDocument")
+    func noJSON() {
+        #expect(throws: ManifestError.self) {
+            try PrinttargManifestExtractor.manifest(from: "plain text\nno json")
+        }
+    }
+
+    @Test("Wrong event → wrongEvent")
+    func wrongEvent() {
+        let stdout = "{\n  \"event\": \"row\",\n  \"row\": 1\n}\n"
+        #expect(throws: ManifestError.self) {
+            try PrinttargManifestExtractor.manifest(from: stdout)
+        }
+    }
+
+    @Test("ROW_COLORS_JSON line is never treated as the manifest")
+    func rowColorsNotManifest() {
+        let stdout = "ROW_COLORS_JSON: {\"a\":1}\n{\"event\":\"manifest\",\"pages\":[]}"
+        // Extraction only starts at a '{' that begins a trimmed line,
+        // so the ROW_COLORS_JSON line is skipped entirely.
+        let m = try? PrinttargManifestExtractor.manifest(from: stdout)
+        #expect(m != nil)
+        #expect(m?.event == "manifest")
+    }
+
+    @Test("Braces inside a quoted filename do not corrupt the scan")
+    func bracesInFilename() throws {
+        let stdout = "log\n{\n\"event\": \"manifest\",\n\"pages\": [{\"filename\": \"a}b.tif\", \"patches\": 1, \"width_mm\": 50, \"height_mm\": 50}]\n}\n"
+        let m = try PrinttargManifestExtractor.manifest(from: stdout)
+        #expect(m.pages[0].filename == "a}b.tif")
+    }
+
+    @Test("Unsafe / non-TIFF filenames rejected")
+    func unsafeFilenames() {
+        for bad in ["../x.tif", "/abs/x.tif", "dir/x.tif", "x.txt", ""] {
+            let stdout = "{\n\"event\":\"manifest\",\"pages\":[{\"filename\":\"\(bad)\",\"patches\":1,\"width_mm\":50,\"height_mm\":50}]\n}"
+            #expect(throws: ManifestError.self) {
+                try PrinttargManifestExtractor.manifest(from: stdout)
+            }
+        }
+    }
+}
+
+@Suite("ArgyllRunner Printtarg")
+struct ArgyllRunnerPrinttargTests {
+
+    private func makeFixture(_ body: String, name: String = "printtarg") throws -> URL {
+        let dir = FileManager.default.temporaryDirectory
+            .appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+        let url = dir.appendingPathComponent(name)
+        try body.write(to: url, atomically: true, encoding: .utf8)
+        try FileManager.default.setAttributes(
+            [.posixPermissions: 0o755], ofItemAtPath: url.path)
+        return dir
+    }
+
+    /// A minimal valid TIFF (8-bit, tiny) for gallery preview tests.
+    private func writeTinyTIFF(at url: URL) throws {
+        // 1x1 8-bit grayscale TIFF, little-endian.
+        var bytes: [UInt8] = [
+            0x49, 0x49, 0x2A, 0x00, // II + magic
+            0x08, 0x00, 0x00, 0x00, // IFD offset
+        ]
+        let ifdCount: UInt16 = 10
+        bytes += withUnsafeBytes(of: ifdCount.littleEndian) { Array($0) }
+        func tag(_ t: UInt16, _ type: UInt16, _ count: UInt32, _ value: UInt32) {
+            bytes += withUnsafeBytes(of: t.littleEndian) { Array($0) }
+            bytes += withUnsafeBytes(of: type.littleEndian) { Array($0) }
+            bytes += withUnsafeBytes(of: count.littleEndian) { Array($0) }
+            bytes += withUnsafeBytes(of: value.littleEndian) { Array($0) }
+        }
+        tag(256, 3, 1, 1)      // ImageWidth = 1
+        tag(257, 3, 1, 1)      // ImageLength = 1
+        tag(258, 3, 1, 8)      // BitsPerSample = 8
+        tag(259, 3, 1, 1)      // Compression = none
+        tag(262, 3, 1, 1)      // Photometric = BlackIsZero
+        tag(273, 4, 1, 0)      // StripOffsets — patched below
+        tag(277, 3, 1, 1)      // SamplesPerPixel = 1
+        tag(278, 3, 1, 1)      // RowsPerStrip = 1
+        tag(279, 4, 1, 1)      // StripByteCounts = 1
+        tag(284, 3, 1, 1)      // PlanarConfig
+        bytes += [0, 0, 0, 0]  // next IFD = none
+        let pixelOffset = bytes.count
+        bytes += [0x80]        // the pixel
+        // Patch StripOffsets (located right after the tag header at
+        // offset 8 + 2 + 5*12 + 8 = position of value field).
+        let valuePos = 8 + 2 + 5 * 12 + 8
+        let off = UInt32(pixelOffset).littleEndian
+        withUnsafeBytes(of: off) { b in
+            bytes[valuePos] = b[0]; bytes[valuePos+1] = b[1]
+            bytes[valuePos+2] = b[2]; bytes[valuePos+3] = b[3]
+        }
+        try Data(bytes).write(to: url)
+    }
+
+    @Test("Successful printtarg emits .ti2 + manifest + PNG previews")
+    func success() async throws {
+        let dir = try makeFixture("""
+            #!/bin/sh
+            last=""
+            for arg in "$@"; do last="$arg"; done
+            printf 'log line\\n'
+            printf '{\\n  "event": "manifest",\\n  "pages": [\\n    {"filename": "%s.tif", "patches": 4, "width_mm": 210, "height_mm": 297}\\n  ]\\n}\\n' "$last"
+            touch "$last.ti2"
+            exit 0
+            """)
+        defer { try? FileManager.default.removeItem(at: dir) }
+        // Basename "pt" → manifest references pt.tif; write a real TIFF.
+        try writeTinyTIFF(at: dir.appendingPathComponent("pt.tif"))
+
+        let resolver = BinaryResolver(bundledRoot: dir, overrideDir: dir)
+        let runner = ArgyllRunner(
+            processManager: ProcessManager(), binaryResolver: resolver)
+        let config = PrinttargConfig(basename: "pt", workingDirectory: dir)
+        let result = try await runner.runPrinttarg(config: config)
+        #expect(result.ti2URL.lastPathComponent == "pt.ti2")
+        #expect(result.manifest.pages.count == 1)
+        #expect(result.pages.count == 1)
+        let png = result.pages[0].previewPNG
+        #expect(png != nil)
+        if let png {
+            #expect(png.prefix(8) == Data([0x89,0x50,0x4E,0x47,0x0D,0x0A,0x1A,0x0A]))
+        }
+    }
+
+    @Test("Non-zero exit throws processFailed and stays on stage")
+    func failure() async throws {
+        let dir = try makeFixture("""
+            #!/bin/sh
+            echo "oops" >&2
+            exit 3
+            """)
+        defer { try? FileManager.default.removeItem(at: dir) }
+        let runner = ArgyllRunner(
+            processManager: ProcessManager(),
+            binaryResolver: BinaryResolver(bundledRoot: dir, overrideDir: dir))
+        await #expect(throws: ArgyllRunnerError.self) {
+            try await runner.runPrinttarg(
+                config: PrinttargConfig(basename: "x", workingDirectory: dir))
+        }
+    }
+
+    @Test("Exit 0 without manifest → malformedManifest")
+    func noManifest() async throws {
+        let dir = try makeFixture("""
+            #!/bin/sh
+            last=""
+            for arg in "$@"; do last="$arg"; done
+            touch "$last.ti2"
+            echo "no json here"
+            exit 0
+            """)
+        defer { try? FileManager.default.removeItem(at: dir) }
+        let runner = ArgyllRunner(
+            processManager: ProcessManager(),
+            binaryResolver: BinaryResolver(bundledRoot: dir, overrideDir: dir))
+        await #expect(throws: ArgyllRunnerError.self) {
+            try await runner.runPrinttarg(
+                config: PrinttargConfig(basename: "x", workingDirectory: dir))
+        }
+    }
+
+    @Test("Exit 0 without .ti2 → missingArtefact")
+    func noTi2() async throws {
+        let dir = try makeFixture("""
+            #!/bin/sh
+            printf '{\\n"event":"manifest",\\n"pages":[]\\n}\\n'
+            exit 0
+            """)
+        defer { try? FileManager.default.removeItem(at: dir) }
+        let runner = ArgyllRunner(
+            processManager: ProcessManager(),
+            binaryResolver: BinaryResolver(bundledRoot: dir, overrideDir: dir))
+        await #expect(throws: ArgyllRunnerError.self) {
+            try await runner.runPrinttarg(
+                config: PrinttargConfig(basename: "x", workingDirectory: dir))
+        }
+    }
+
+    @Test("Deterministic config produces byte-identical .ti2")
+    func determinism() async throws {
+        let dir = try makeFixture("""
+            #!/bin/sh
+            last=""
+            for arg in "$@"; do last="$arg"; done
+            printf 'TI2\\nDETERMINISTIC\\n' > "$last.ti2"
+            printf '{\\n"event":"manifest",\\n"pages":[]\\n}\\n'
+            exit 0
+            """)
+        defer { try? FileManager.default.removeItem(at: dir) }
+        let runner = ArgyllRunner(
+            processManager: ProcessManager(),
+            binaryResolver: BinaryResolver(bundledRoot: dir, overrideDir: dir))
+        // Two runs, two basenames — same argv except basename.
+        _ = try await runner.runPrinttarg(
+            config: PrinttargConfig(basename: "a", workingDirectory: dir))
+        _ = try await runner.runPrinttarg(
+            config: PrinttargConfig(basename: "b", workingDirectory: dir))
+        let d1 = try Data(contentsOf: dir.appendingPathComponent("a.ti2"))
+        let d2 = try Data(contentsOf: dir.appendingPathComponent("b.ti2"))
+        #expect(d1 == d2)
+    }
+}
diff --git a/Tests/ICCeryCoreTests/TargenTests.swift b/Tests/ICCeryCoreTests/TargenTests.swift
new file mode 100644
index 0000000..3329bcc
--- /dev/null
+++ b/Tests/ICCeryCoreTests/TargenTests.swift
@@ -0,0 +1,330 @@
+import Testing
+import Foundation
+@testable import ICCeryCore
+
+@Suite("TargenArgs")
+struct TargenArgsTests {
+
+    @Test("RGB baseline: -v -d 2 -f 800 -e 4 -B 4")
+    func rgbBaseline() throws {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            basename: "test_rgb"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(args == ["-v", "-d", "2", "-f", "800", "-e", "4", "-B", "4", "test_rgb"])
+        #expect(!args.contains("-u"))
+    }
+
+    @Test("CMYK baseline: -v -d 4 -f 1500 -e 4 -B 0")
+    func cmykBaseline() throws {
+        let config = TargenConfig(
+            colourSpace: .cmyk,
+            patchCount: 1500,
+            whitePatches: 4,
+            blackPatches: 0,
+            basename: "test_cmyk"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(args == ["-v", "-d", "4", "-f", "1500", "-e", "4", "-B", "0", "test_cmyk"])
+    }
+
+    @Test("Custom patch count honours -f (#44)")
+    func customPatchCount() throws {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 2500,
+            whitePatches: 4,
+            blackPatches: 4,
+            basename: "custom_patches"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(args.contains("-f"))
+        #expect(args[args.firstIndex(of: "-f")! + 1] == "2500")
+    }
+
+    @Test("All advanced flags in stable order")
+    func allAdvancedFlags() throws {
+        let config = TargenConfig(
+            colourSpace: .cmyk,
+            patchCount: 1200,
+            whitePatches: 6,
+            blackPatches: 2,
+            greySteps: 12,
+            singleChannelSteps: 8,
+            neutralSteps: 6,
+            neutralConcentration: 0.75,
+            preconditioningProfile: "/path/to/profile.icc",
+            ofpsHighQuality: true,
+            ofpsAdaptation: 0.10,
+            fullSpreadAlgorithm: .target,
+            totalInkLimit: 320,
+            darkEmphasis: 1.50,
+            devicePower: 2.0,
+            basename: "advanced_cmyk"
+        )
+        let args = try TargenArgs.build(config: config)
+        let expected = [
+            "-v", "-d", "4",
+            "-f", "1200",
+            "-e", "6",
+            "-B", "2",
+            "-g", "12",
+            "-s", "8",
+            "-n", "6",
+            "-N", "0.75",
+            "-c", "/path/to/profile.icc",
+            "-G",
+            "-A", "0.10",
+            "-t",
+            "-l", "320",
+            "-V", "1.50",
+            "-p", "2.00",
+            "advanced_cmyk"
+        ]
+        #expect(args == expected)
+    }
+
+    @Test("RGB ignores total ink limit")
+    func rgbIgnoresInkLimit() throws {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            totalInkLimit: 300,
+            basename: "rgb_no_ink"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(!args.contains("-l"))
+    }
+
+    @Test("Neutral concentration omitted when approximately 0.50")
+    func neutralConcentrationOmittedWhenDefault() throws {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            neutralConcentration: 0.5005,
+            basename: "n_default"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(!args.contains("-N"))
+    }
+
+    @Test("Adaptation emitted even at 0.10 (no default-skip)")
+    func adaptationEmittedAtPointOne() throws {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            ofpsAdaptation: 0.10,
+            basename: "a_flag"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(args.contains("-A"))
+        #expect(args[args.firstIndex(of: "-A")! + 1] == "0.10")
+    }
+
+    @Test("OFPS full spread algorithm emits no flag")
+    func ofpsEmitsNoFlag() throws {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            fullSpreadAlgorithm: .ofps,
+            basename: "ofps_test"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(!args.contains("ofps"))
+        #expect(!args.contains("-t"))
+    }
+
+    @Test("Dark emphasis and device power omitted when 1.0")
+    func darkEmphasisAndPowerOmittedWhenOne() throws {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            darkEmphasis: 1.0,
+            devicePower: 1.0,
+            basename: "defaults_omitted"
+        )
+        let args = try TargenArgs.build(config: config)
+        #expect(!args.contains("-V"))
+        #expect(!args.contains("-p"))
+    }
+
+    @Test("Invalid basename throws")
+    func invalidBasenameThrows() {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            basename: "../bad_name"
+        )
+        #expect(throws: PathSecurity.Error.self) {
+            try TargenArgs.build(config: config)
+        }
+    }
+
+    @Test("Invalid patch count throws")
+    func invalidPatchCountThrows() {
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 0,
+            whitePatches: 4,
+            blackPatches: 4,
+            basename: "bad_count"
+        )
+        #expect(throws: TargenArgError.self) {
+            try TargenArgs.build(config: config)
+        }
+    }
+
+    @Test("Invalid ink limit throws for CMYK")
+    func invalidInkLimitThrows() {
+        let config = TargenConfig(
+            colourSpace: .cmyk,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 0,
+            totalInkLimit: 450,
+            basename: "bad_ink"
+        )
+        #expect(throws: TargenArgError.self) {
+            try TargenArgs.build(config: config)
+        }
+    }
+}
+
+@Suite("ArgyllRunner Targen")
+struct ArgyllRunnerTargenTests {
+
+    @Test("Successful targen execution creates .ti1 and returns URL")
+    func successfulTargenExecution() async throws {
+        let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
+        defer { try? FileManager.default.removeItem(at: tempDir) }
+
+        // Create a mock targen script
+        let mockScript = """
+        #!/bin/sh
+        # Find the last argument which is the basename
+        for arg do shift; set -- "$@" "$arg"; done
+        last="$arg"
+        echo "Generating patches..."
+        touch "$last.ti1"
+        echo "Done!"
+        exit 0
+        """
+        let mockURL = tempDir.appendingPathComponent("targen")
+        try mockScript.write(to: mockURL, atomically: true, encoding: .utf8)
+        try FileManager.default.setAttributes([.posixPermissions: 0o755], ofItemAtPath: mockURL.path)
+
+        let resolver = BinaryResolver(bundledRoot: tempDir, overrideDir: tempDir)
+        let pm = ProcessManager()
+        let runner = ArgyllRunner(processManager: pm, binaryResolver: resolver)
+
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            basename: "mock_test",
+            workingDirectory: tempDir
+        )
+
+        var logLines: [String] = []
+        final class LogBox: @unchecked Sendable {
+            var lines: [String] = []
+            let lock = NSLock()
+            func append(_ batch: [String]) {
+                lock.lock(); lines.append(contentsOf: batch); lock.unlock()
+            }
+        }
+        let box = LogBox()
+        let ti1URL = try await runner.runTargen(config: config) { batch in
+            box.append(batch)
+        }
+        logLines = box.lines
+        #expect(logLines.contains("Generating patches..."))
+
+        #expect(FileManager.default.fileExists(atPath: ti1URL.path))
+        #expect(ti1URL.lastPathComponent == "mock_test.ti1")
+    }
+
+    @Test("Failed targen execution throws processFailed")
+    func failedTargenExecution() async throws {
+        let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
+        defer { try? FileManager.default.removeItem(at: tempDir) }
+
+        let mockScript = """
+        #!/bin/sh
+        echo "Error: something went wrong" >&2
+        exit 1
+        """
+        let mockURL = tempDir.appendingPathComponent("targen")
+        try mockScript.write(to: mockURL, atomically: true, encoding: .utf8)
+        try FileManager.default.setAttributes([.posixPermissions: 0o755], ofItemAtPath: mockURL.path)
+
+        let resolver = BinaryResolver(bundledRoot: tempDir, overrideDir: tempDir)
+        let pm = ProcessManager()
+        let runner = ArgyllRunner(processManager: pm, binaryResolver: resolver)
+
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            basename: "fail_test",
+            workingDirectory: tempDir
+        )
+
+        await #expect(throws: ArgyllRunnerError.self) {
+            try await runner.runTargen(config: config)
+        }
+    }
+
+    @Test("Targen exit 0 without .ti1 throws missingArtefact")
+    func missingArtefactThrows() async throws {
+        let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
+        defer { try? FileManager.default.removeItem(at: tempDir) }
+
+        let mockScript = """
+        #!/bin/sh
+        echo "Exited 0 but did not create file"
+        exit 0
+        """
+        let mockURL = tempDir.appendingPathComponent("targen")
+        try mockScript.write(to: mockURL, atomically: true, encoding: .utf8)
+        try FileManager.default.setAttributes([.posixPermissions: 0o755], ofItemAtPath: mockURL.path)
+
+        let resolver = BinaryResolver(bundledRoot: tempDir, overrideDir: tempDir)
+        let pm = ProcessManager()
+        let runner = ArgyllRunner(processManager: pm, binaryResolver: resolver)
+
+        let config = TargenConfig(
+            colourSpace: .rgb,
+            patchCount: 800,
+            whitePatches: 4,
+            blackPatches: 4,
+            basename: "no_file",
+            workingDirectory: tempDir
+        )
+
+        await #expect(throws: ArgyllRunnerError.self) {
+            try await runner.runTargen(config: config)
+        }
+    }
+}
diff --git a/Tests/ICCeryUITests/Fixtures/bin/printtarg b/Tests/ICCeryUITests/Fixtures/bin/printtarg
new file mode 100755
index 0000000..16f482d
--- /dev/null
+++ b/Tests/ICCeryUITests/Fixtures/bin/printtarg
@@ -0,0 +1,14 @@
+#!/bin/sh
+# Mock printtarg for Milestone2UITests. Writes one 2x2 TIFF, a pretty
+# manifest on stdout, and a fake .ti2 next to the basename (last argv).
+# Exit code is overridable via ICCERY_MOCK_PRINTTARG_EXIT.
+last=""
+for arg in "$@"; do last="$arg"; done
+if [ "${ICCERY_MOCK_PRINTTARG_EXIT:-0}" -ne 0 ]; then
+  echo "mock printtarg failure" >&2
+  exit "$ICCERY_MOCK_PRINTTARG_EXIT"
+fi
+echo 'SUkqAAgAAAAKAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwABAAAACAAAAAMBAwABAAAAAQAAAAYBAwABAAAAAQAAABEBBAABAAAAhgAAABUBAwABAAAAAQAAABYBAwABAAAAAgAAABcBBAABAAAABAAAABwBAwABAAAAAQAAAAAAAAA8eLTw' | /usr/bin/base64 -D > "page1.tif"
+printf '{\n  "event": "manifest",\n  "pages": [\n    {"filename": "page1.tif", "patches": 4, "width_mm": 210, "height_mm": 297}\n  ]\n}\n'
+touch "$last.ti2"
+exit 0
diff --git a/Tests/ICCeryUITests/Fixtures/bin/targen b/Tests/ICCeryUITests/Fixtures/bin/targen
new file mode 100755
index 0000000..d5f46c5
--- /dev/null
+++ b/Tests/ICCeryUITests/Fixtures/bin/targen
@@ -0,0 +1,13 @@
+#!/bin/sh
+# Mock targen for Milestone2UITests. Emits a fake .ti1 next to the
+# basename (last argv) in the process working directory. Exit code is
+# overridable via ICCERY_MOCK_TARGEN_EXIT.
+last=""
+for arg in "$@"; do last="$arg"; done
+echo "targen mock: generating $last"
+if [ "${ICCERY_MOCK_TARGEN_EXIT:-0}" -ne 0 ]; then
+  echo "mock targen failure" >&2
+  exit "$ICCERY_MOCK_TARGEN_EXIT"
+fi
+touch "$last.ti1"
+exit 0
diff --git a/Tests/ICCeryUITests/Milestone2UITests.swift b/Tests/ICCeryUITests/Milestone2UITests.swift
new file mode 100644
index 0000000..cc6919e
--- /dev/null
+++ b/Tests/ICCeryUITests/Milestone2UITests.swift
@@ -0,0 +1,355 @@
+import XCTest
+
+/// Milestone 2 UI tests — issues #7–#11 (docs/21 element contract).
+/// Every test launches the app with an isolated `ICCERY_TEST_ROOT`,
+/// fixture sidecars via `ICCERY_ARGYLL_BINARY_DIR`, and
+/// `ICCERY_UI_TESTING=1` so file dialogs resolve to env-provided
+/// paths instead of modal panels. No hardware, no network, no real
+/// Argyll install, and nothing is written to the developer's app data.
+@MainActor
+final class Milestone2UITests: XCTestCase {
+
+    private var app: XCUIApplication!
+    private var testRoot: URL!
+    private var binDir: URL!
+    private var workDir: URL!
+
+    override func setUp() async throws {
+        continueAfterFailure = false
+        // The xctrunner sandbox only permits writes inside its own
+        // container — the work dir lives there (the app can read/write
+        // it). Executable fixtures, however, must live outside the
+        // container or the app-under-test cannot posix_spawn them, so
+        // `bin` points at the committed Fixtures/bin scripts in the
+        // repo checkout (resolved via #filePath).
+        testRoot = FileManager.default.temporaryDirectory
+            .appendingPathComponent("iccery-ui-\(UUID().uuidString)")
+        binDir = URL(fileURLWithPath: #filePath)
+            .deletingLastPathComponent()        // Tests/ICCeryUITests
+            .appendingPathComponent("Fixtures/bin")
+        workDir = testRoot.appendingPathComponent("work")
+        try FileManager.default.createDirectory(
+            at: workDir, withIntermediateDirectories: true)
+
+        app = XCUIApplication()
+        app.launchEnvironment = [
+            "ICCERY_UI_TESTING": "1",
+            "ICCERY_TEST_ROOT": testRoot.path,
+            "ICCERY_ARGYLL_BINARY_DIR": binDir.path,
+            "ICCERY_TEST_SAVE_TARGET":
+                workDir.appendingPathComponent("mytarget.ti1").path,
+            "ICCERY_TEST_WORKDIR": workDir.path,
+        ]
+    }
+
+    override func tearDown() async throws {
+        app?.terminate()
+        app = nil
+        if let testRoot {
+            try? FileManager.default.removeItem(at: testRoot)
+        }
+        testRoot = nil
+    }
+
+    /// Force the fixture printtarg to exit with `code`.
+    private func failPrinttarg(exitCode: Int) {
+        app.launchEnvironment["ICCERY_MOCK_PRINTTARG_EXIT"] = "\(exitCode)"
+    }
+
+    /// Launch and bring the app to the front — other app windows
+    /// (the IDE, notification banners) covering the test window count
+    /// as "interrupting elements" and stall synthesized clicks.
+    private func launchApp() {
+        app.launch()
+        app.activate()
+    }
+
+    /// Sheet content on macOS lives under `app.sheets`, outside the
+    /// main window's descendant tree — probe both scopes.
+    private func element(_ id: String) -> XCUIElement {
+        let inApp = app.descendants(matching: .any)[id]
+        if inApp.exists { return inApp }
+        return app.sheets.firstMatch.descendants(matching: .any)[id]
+    }
+
+    private func waitFor(_ id: String, timeout: TimeInterval = 10) -> XCUIElement {
+        // Poll both scopes so sheet-hosted elements resolve too.
+        let deadline = Date().addingTimeInterval(timeout)
+        while Date() < deadline {
+            let el = element(id)
+            if el.exists { return el }
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        let el = element(id)
+        XCTAssertTrue(el.exists, "Expected element \(id)")
+        return el
+    }
+
+    private func staticText(_ exact: String) -> XCUIElement {
+        let inApp = app.staticTexts[exact]
+        if inApp.exists { return inApp }
+        return app.sheets.firstMatch.staticTexts[exact]
+    }
+
+    private func buttonsMatching(_ predicateFormat: String) -> XCUIElementQuery {
+        let pred = NSPredicate(format: predicateFormat)
+        let inApp = app.buttons.matching(pred)
+        if inApp.count > 0 { return inApp }
+        return app.sheets.firstMatch.buttons.matching(pred)
+    }
+
+    // MARK: - Tests
+
+    /// Stage 1 opens with the Standard 800-patch default; Generate stays
+    /// disabled until basename + cwd are valid (issue #7).
+    func testStage1DefaultsAndGenerateGate() throws {
+        launchApp()
+        XCTAssertTrue(waitFor("btnGenerate").exists)
+        XCTAssertTrue(element("patchCountPreset").exists)
+        XCTAssertTrue(element("targetBasename").exists)
+        XCTAssertTrue(element("btnOpenExisting").exists)
+        XCTAssertFalse(app.buttons["btnGenerate"].isEnabled)
+
+        // Browse fills basename + working dir via the test hook.
+        app.buttons["btnBrowse"].click()
+        XCTAssertTrue(app.buttons["btnGenerate"].isEnabled)
+    }
+
+    /// RGB/CMYK + advanced controls expose the documented identifiers
+    /// and the ink-limit group is hidden for RGB (issue #7).
+    func testStage1AdvancedVisibility() throws {
+        launchApp()
+        XCTAssertTrue(waitFor("targenAdvancedDetails").exists)
+        // RGB default: ink-limit group must not exist.
+        XCTAssertFalse(element("targenInkLimitGroup").exists)
+        // The ink-limit group lives inside the Advanced disclosure —
+        // pre-expanded under UI testing (XCUI can't toggle a macOS
+        // DisclosureTriangle reliably). Switch the picker to CMYK.
+        XCTAssertTrue(element("targenAdvancedDetails").exists)
+        let cmyk = app.radioGroups["colourSpace"]
+            .radioButtons["CMYK (RIP output)"]
+        XCTAssertTrue(cmyk.waitForExistence(timeout: 5))
+        cmyk.click()
+        XCTAssertTrue(element("targenInkLimitGroup").waitForExistence(timeout: 5))
+    }
+
+    /// Fixture-backed targen run creates .ti1 and unlocks Stage 2.
+    func testTargenFixtureUnlocksStage2() throws {
+        launchApp()
+        app.buttons["btnBrowse"].click()
+        app.buttons["btnGenerate"].click()
+        XCTAssertTrue(waitFor("btnCreateLayout", timeout: 20).exists)
+        XCTAssertTrue(FileManager.default.fileExists(
+            atPath: workDir.appendingPathComponent("mytarget.ti1").path))
+    }
+
+    /// Fixture printtarg → .ti2, gallery page renders, print controls
+    /// stay disabled, Stage 3 advance becomes available (issues #9/#10).
+    func testPrinttargFixtureGalleryAndStubbedPrint() throws {
+        launchApp()
+
+        app.buttons["btnBrowse"].click()
+        app.buttons["btnGenerate"].click()
+        XCTAssertTrue(waitFor("btnCreateLayout", timeout: 20).exists)
+
+        // Colour-management warning is always present on Stage 2.
+        XCTAssertTrue(element("cmWarningBanner").exists)
+        XCTAssertTrue(element("instrumentSelect").exists)
+        XCTAssertTrue(element("pageSizeSelect").exists)
+        XCTAssertTrue(element("tiffDpi").exists)
+        XCTAssertTrue(element("targetLabelPreview").exists)
+
+        app.buttons["btnCreateLayout"].click()
+        XCTAssertTrue(waitFor("galleryPage-0", timeout: 20).exists)
+        XCTAssertTrue(FileManager.default.fileExists(
+            atPath: workDir.appendingPathComponent("mytarget.ti2").path))
+
+        // M3 stubs: visible but inert.
+        XCTAssertTrue(element("rawPrintPanel").exists)
+        XCTAssertFalse(app.buttons["btnPrintAll"].isEnabled)
+        XCTAssertFalse(app.buttons["btnPrintPage-0"].isEnabled)
+        XCTAssertTrue(app.buttons["btnAdvanceToStage3"].isEnabled)
+    }
+
+    /// A failed printtarg run stays on Stage 2 (non-zero exit, #156).
+    func testPrinttargFailureStaysOnStage2() throws {
+        failPrinttarg(exitCode: 3)
+        launchApp()
+        app.buttons["btnBrowse"].click()
+        app.buttons["btnGenerate"].click()
+        XCTAssertTrue(waitFor("btnCreateLayout", timeout: 20).exists)
+
+        app.buttons["btnCreateLayout"].click()
+        // The notice banner reports the failure and we never advance:
+        // btnCreateLayout is still the stage's action, and no gallery
+        // appears.
+        let failureText = element("noticeText")
+        XCTAssertTrue(failureText.waitForExistence(timeout: 20))
+        XCTAssertTrue((failureText.value as? String ?? "")
+            .contains("printtarg failed"))
+        XCTAssertTrue(element("btnCreateLayout").exists)
+        XCTAssertFalse(element("galleryPage-0").exists)
+        XCTAssertFalse(FileManager.default.fileExists(
+            atPath: workDir.appendingPathComponent("mytarget.ti2").path))
+    }
+
+    /// Resume: .ti1 jumps to Stage 2 (issue #8).
+    func testResumeTi1() throws {
+        FileManager.default.createFile(
+            atPath: workDir.appendingPathComponent("old.ti1").path,
+            contents: Data("CGATS".utf8))
+        app.launchEnvironment["ICCERY_TEST_EXISTING_TARGET"] =
+            workDir.appendingPathComponent("old.ti1").path
+        launchApp()
+        app.buttons["btnOpenExisting"].click()
+        XCTAssertTrue(waitFor("btnCreateLayout", timeout: 10).exists)
+    }
+
+    /// Resume: .ti2 with sibling .ti1 reaches the Stage 3 shell and
+    /// shows the persisted "Resumed from .ti2" state (issue #8).
+    func testResumeTi2ShowsStage3AndNotice() throws {
+        FileManager.default.createFile(
+            atPath: workDir.appendingPathComponent("old.ti1").path,
+            contents: Data("CGATS".utf8))
+        FileManager.default.createFile(
+            atPath: workDir.appendingPathComponent("old.ti2").path,
+            contents: Data("""
+                CTI2
+                TARGET_INSTRUMENT "i1"
+                NUMBER_OF_SETS 4
+                NUMBER_OF_PAGES 1
+                BEGIN_DATA_FORMAT
+                """.utf8))
+        app.launchEnvironment["ICCERY_TEST_EXISTING_TARGET"] =
+            workDir.appendingPathComponent("old.ti2").path
+        launchApp()
+        app.buttons["btnOpenExisting"].click()
+        XCTAssertTrue(waitFor("stage3TargetBasename", timeout: 10).exists)
+        XCTAssertTrue(element("stage3LoadedTargetBanner").exists)
+        let notice = element("noticeText")
+        XCTAssertTrue(notice.exists)
+        XCTAssertTrue((notice.value as? String ?? "")
+            .contains("Resumed from .ti2"))
+    }
+
+    /// A .ti2 without its sibling .ti1 must not advance (issue #8).
+    func testResumeTi2WithoutSiblingFails() throws {
+        FileManager.default.createFile(
+            atPath: workDir.appendingPathComponent("orphan.ti2").path,
+            contents: Data("CTI2".utf8))
+        app.launchEnvironment["ICCERY_TEST_EXISTING_TARGET"] =
+            workDir.appendingPathComponent("orphan.ti2").path
+        launchApp()
+        app.buttons["btnOpenExisting"].click()
+        let err = element("noticeText")
+        XCTAssertTrue(err.waitForExistence(timeout: 10))
+        XCTAssertTrue((err.value as? String ?? "").contains("Cannot resume"))
+        XCTAssertTrue(element("btnGenerate").exists) // still Stage 1
+    }
+
+    /// Preset apply is bidirectional: the draft preset's 150 dpi must
+    /// be visible on Stage 2; built-ins cannot be deleted (issue #11).
+    func testPresetApplyAndBuiltInProtection() throws {
+        // Land on Stage 2 via a .ti1 resume so tiffDpi is visible.
+        FileManager.default.createFile(
+            atPath: workDir.appendingPathComponent("p.ti1").path,
+            contents: Data("CGATS".utf8))
+        app.launchEnvironment["ICCERY_TEST_EXISTING_TARGET"] =
+            workDir.appendingPathComponent("p.ti1").path
+        launchApp()
+
+        // Sidebar preset picker is enabled; apply the draft preset.
+        let picker = app.popUpButtons["presetSelect"]
+        XCTAssertTrue(picker.waitForExistence(timeout: 10))
+        XCTAssertTrue(picker.isEnabled)
+        picker.click()
+        let draftItem = app.menuItems["Fast RGB Draft (400 patches)"]
+        XCTAssertTrue(draftItem.waitForExistence(timeout: 5))
+        draftItem.click()
+
+        app.buttons["btnOpenExisting"].click()
+        XCTAssertTrue(waitFor("btnCreateLayout", timeout: 10).exists)
+        // StaticText content is exposed via `value` on macOS, not `label`.
+        XCTAssertTrue(app.staticTexts
+            .matching(NSPredicate(format: "value CONTAINS 'DPI: 150'"))
+            .firstMatch.waitForExistence(timeout: 5))
+
+        // Manage dialog: built-ins show "Built-in" and have no delete.
+        app.buttons["btnOpenPresetsDialog"].click()
+        XCTAssertTrue(waitFor("managePresetsList", timeout: 10).exists)
+        XCTAssertFalse(element("btnDeletePreset-preset-std-rgb").exists)
+        XCTAssertTrue(element("presetRow-preset-std-rgb").exists)
+        element("btnCloseManagePresetsDialog").click()
+    }
+
+    /// Save a custom preset through the dialog; it appears in the list
+    /// and can be deleted (issue #11).
+    func testSaveAndDeleteCustomPreset() throws {
+        launchApp()
+        app.buttons["btnSavePresetModal"].click()
+        XCTAssertTrue(waitFor("savePresetDialog", timeout: 10).exists)
+        let nameField = element("savePresetName")
+        XCTAssertTrue(nameField.waitForExistence(timeout: 5))
+        nameField.click()
+        nameField.typeText("UI Test Preset")
+        element("btnConfirmSavePreset").click()
+
+        app.buttons["btnOpenPresetsDialog"].click()
+        XCTAssertTrue(waitFor("managePresetsList", timeout: 10).exists)
+        XCTAssertTrue(staticText("UI Test Preset")
+            .waitForExistence(timeout: 5))
+        // The custom row is deletable (id prefix custom-).
+        let deleteButtons = buttonsMatching(
+            "identifier BEGINSWITH 'btnDeletePreset-'")
+        XCTAssertTrue(deleteButtons.firstMatch.waitForExistence(timeout: 5))
+        deleteButtons.firstMatch.click()
+        XCTAssertFalse(staticText("UI Test Preset").waitForExistence(timeout: 3))
+    }
+
+    /// Export a preset to JSON and re-import it (issue #11).
+    func testPresetExportImport() throws {
+        let exportURL = testRoot.appendingPathComponent("export.json")
+        let importURL = testRoot.appendingPathComponent("import.json")
+        app.launchEnvironment["ICCERY_TEST_PRESET_EXPORT"] = exportURL.path
+        app.launchEnvironment["ICCERY_TEST_PRESET_IMPORT"] = importURL.path
+        launchApp()
+
+        // Save a custom preset first, then export it.
+        app.buttons["btnSavePresetModal"].click()
+        let nameField = element("savePresetName")
+        XCTAssertTrue(nameField.waitForExistence(timeout: 10))
+        nameField.click()
+        nameField.typeText("RoundTrip")
+        element("btnConfirmSavePreset").click()
+
+        // Export via the manage dialog.
+        app.buttons["btnOpenPresetsDialog"].click()
+        XCTAssertTrue(waitFor("managePresetsList", timeout: 10).exists)
+        let exportButtons = buttonsMatching(
+            "identifier BEGINSWITH 'btnExportPreset-'")
+        XCTAssertTrue(exportButtons.firstMatch.waitForExistence(timeout: 5))
+        exportButtons.firstMatch.click()
+        XCTAssertTrue(waitForFile(exportURL), "preset export file missing")
+
+        // Import must land back in the store (delete → re-import).
+        let deleteButtons = buttonsMatching(
+            "identifier BEGINSWITH 'btnDeletePreset-'")
+        deleteButtons.firstMatch.click()
+        XCTAssertFalse(staticText("RoundTrip").waitForExistence(timeout: 3))
+
+        // Copy the export to the import path so the hook picks it up.
+        try FileManager.default.copyItem(at: exportURL, to: importURL)
+        element("btnImportPreset").click()
+        XCTAssertTrue(staticText("RoundTrip")
+            .waitForExistence(timeout: 5))
+    }
+
+    private func waitForFile(_ url: URL, timeout: TimeInterval = 5) -> Bool {
+        let deadline = Date().addingTimeInterval(timeout)
+        while Date() < deadline {
+            if FileManager.default.fileExists(atPath: url.path) { return true }
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        return false
+    }
+}
diff --git a/project.yml b/project.yml
index 1afb884..d5014f6 100644
--- a/project.yml
+++ b/project.yml
@@ -81,12 +81,29 @@ targets:
         SWIFT_VERSION: "6.0"
         MACOSX_DEPLOYMENT_TARGET: "14.0"
 
+  ICCeryUITests:
+    type: bundle.ui-testing
+    platform: macOS
+    deploymentTarget: "14.0"
+    sources:
+      - path: Tests/ICCeryUITests
+    dependencies:
+      - target: ICCery
+    settings:
+      base:
+        TEST_TARGET_NAME: ICCery
+        GENERATE_INFOPLIST_FILE: YES
+        CODE_SIGN_IDENTITY: "-"
+        SWIFT_VERSION: "6.0"
+        MACOSX_DEPLOYMENT_TARGET: "14.0"
+
 schemes:
   ICCery:
     build:
       targets:
         ICCery: all
         ICCeryCoreTests: [test]
+        ICCeryUITests: [test]
     run:
       config: Debug
     test:
@@ -94,3 +111,4 @@ schemes:
       gatherCoverageData: false
       targets:
         - ICCeryCoreTests
+        - ICCeryUITests