diff --git a/Sources/Kapture/ResultWindow.swift b/Sources/Kapture/ResultWindow.swift
index bf2ab01..9524bda 100644
--- a/Sources/Kapture/ResultWindow.swift
+++ b/Sources/Kapture/ResultWindow.swift
@@ -92,10 +92,14 @@ final class CaptureModel: ObservableObject {
     @Published var selection: CGRect?
     /// Freehand drawing strokes in IMAGE point space
     @Published var strokes: [[CGPoint]] = []
+    /// Redo stack of removed strokes
+    @Published var redoStack: [[CGPoint]] = []
     /// Whether the pen is active (drag draws instead of selecting)
     @Published var isDrawing = false
     /// Current drawing color
     @Published var drawColor: NSColor = .systemRed
+    /// Stroke thickness in points (image space)
+    @Published var strokeWidth: CGFloat = 3.0
 
     enum CaptureMode {
         case screenshot
@@ -107,6 +111,23 @@ final class CaptureModel: ObservableObject {
     }
 
     var hasSelection: Bool { selection != nil && selection!.width >= 2 && selection!.height >= 2 }
+    var canUndo: Bool { !strokes.isEmpty }
+    var canRedo: Bool { !redoStack.isEmpty }
+
+    func undoStroke() {
+        guard let last = strokes.popLast() else { return }
+        redoStack.append(last)
+    }
+
+    func redoStroke() {
+        guard let last = redoStack.popLast() else { return }
+        strokes.append(last)
+    }
+
+    func clearAnnotations() {
+        strokes = []
+        redoStack = []
+    }
 
     /// Image with drawn strokes flattened in, for copy/save/export.
     var annotatedImage: CGImage {
@@ -123,7 +144,7 @@ final class CaptureModel: ObservableObject {
         // CGImage draws with a flipped Y in NSGraphicsContext
         ctx.draw(image, in: NSRect(origin: .zero, size: size))
         drawColor.setStroke()
-        ctx.setLineWidth(3)
+        ctx.setLineWidth(strokeWidth)
         ctx.setLineCap(.round)
         ctx.setLineJoin(.round)
         for stroke in strokes {
@@ -142,10 +163,7 @@ final class CaptureModel: ObservableObject {
     func addStroke(_ points: [CGPoint]) {
         guard points.count > 1 else { return }
         strokes.append(points)
-    }
-
-    func clearAnnotations() {
-        strokes = []
+        redoStack = []
     }
 
     var displayText: String {
@@ -297,15 +315,37 @@ struct ResultView: View {
                     .help("Drawing color")
                 }
 
-                if !model.strokes.isEmpty {
-                    Button {
-                        model.clearAnnotations()
-                    } label: {
-                        Label("Clear", systemImage: "eraser")
+                if model.isDrawing || !model.strokes.isEmpty {
+                    HStack(spacing: 6) {
+                        Button {
+                            model.undoStroke()
+                        } label: {
+                            Image(systemName: "arrow.uturn.backward")
+                        }
+                        .buttonStyle(.bordered)
+                        .disabled(!model.canUndo)
+                        .keyboardShortcut("z", modifiers: .command)
+                        .help("Undo last stroke (⌘Z)")
+
+                        Button {
+                            model.redoStroke()
+                        } label: {
+                            Image(systemName: "arrow.uturn.forward")
+                        }
+                        .buttonStyle(.bordered)
+                        .disabled(!model.canRedo)
+                        .keyboardShortcut("z", modifiers: [.command, .shift])
+                        .help("Redo stroke (⌘⇧Z)")
+
+                        Button {
+                            model.clearAnnotations()
+                        } label: {
+                            Image(systemName: "eraser")
+                        }
+                        .buttonStyle(.bordered)
+                        .disabled(model.strokes.isEmpty)
+                        .help("Remove all drawn annotations")
                     }
-                    .buttonStyle(.bordered)
-                    .foregroundStyle(.secondary)
-                    .help("Remove all drawn annotations")
                 }
 
                 Button {
@@ -338,6 +378,64 @@ struct ResultView: View {
 
             Divider()
 
+            // Draw toolbar (only when drawing)
+            if model.isDrawing {
+                HStack(spacing: 14) {
+                    Label("Draw", systemImage: "pencil.tip")
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+
+                    Divider().frame(height: 18)
+
+                    HStack(spacing: 6) {
+                        Image(systemName: "circle.fill").font(.system(size: 4))
+                        Image(systemName: "circle.fill").font(.system(size: 7))
+                        Image(systemName: "circle.fill").font(.system(size: 10))
+                    }
+                    .foregroundStyle(.secondary)
+                    Slider(value: $model.strokeWidth, in: 1...12, step: 0.5)
+                        .frame(width: 120)
+                        .help("Stroke thickness")
+
+                    Divider().frame(height: 18)
+
+                    ColorPicker("", selection: Binding(
+                        get: { Color(nsColor: model.drawColor) },
+                        set: { model.drawColor = NSColor($0) }
+                    ), supportsOpacity: false)
+                    .labelsHidden()
+                    .frame(width: 28)
+                    .help("Drawing color")
+
+                    Spacer()
+
+                    Button {
+                        model.undoStroke()
+                    } label: {
+                        Label("Undo", systemImage: "arrow.uturn.backward")
+                    }
+                    .buttonStyle(.bordered)
+                    .controlSize(.small)
+                    .disabled(!model.canUndo)
+                    .help("Undo last stroke (⌘Z)")
+
+                    Button {
+                        model.redoStroke()
+                    } label: {
+                        Label("Redo", systemImage: "arrow.uturn.forward")
+                    }
+                    .buttonStyle(.bordered)
+                    .controlSize(.small)
+                    .disabled(!model.canRedo)
+                    .help("Redo stroke (⌘⇧Z)")
+                }
+                .padding(.horizontal, 14)
+                .padding(.vertical, 8)
+                .background(.bar)
+
+                Divider()
+            }
+
             // Content
             if model.mode == .screenshot {
                 ScreenshotPane(model: model)
@@ -441,7 +539,7 @@ struct ScreenshotPane: View {
                             path.addLine(to: CGPoint(x: origin.x + point.x * scale, y: origin.y + point.y * scale))
                         }
                     }
-                    context.stroke(path, with: .color(Color(nsColor: model.drawColor)), lineWidth: 2.5)
+                    context.stroke(path, with: .color(Color(nsColor: model.drawColor)), lineWidth: model.strokeWidth)
                 }
                 .allowsHitTesting(false)
 
@@ -455,7 +553,7 @@ struct ScreenshotPane: View {
                                 path.addLine(to: CGPoint(x: origin.x + point.x * scale, y: origin.y + point.y * scale))
                             }
                         }
-                        context.stroke(path, with: .color(Color(nsColor: model.drawColor)), lineWidth: 2.5)
+                        context.stroke(path, with: .color(Color(nsColor: model.drawColor)), lineWidth: model.strokeWidth)
                     }
                     .allowsHitTesting(false)
                 }
diff --git a/build-app.sh b/build-app.sh
index dc7aa22..d19934a 100755
--- a/build-app.sh
+++ b/build-app.sh
@@ -108,9 +108,9 @@ cat > "$APP/Contents/Info.plist" <<'PLIST'
     <key>CFBundleIconFile</key>
     <string>Icon</string>
     <key>CFBundleShortVersionString</key>
-    <string>1.3.3</string>
+    <string>1.4.0</string>
     <key>CFBundleVersion</key>
-    <string>33</string>
+    <string>40</string>
     <key>LSUIElement</key>
     <true/>
     <key>NSHighResolutionCapable</key>