Selection

Selections define where subsequent operations apply: clearing, copying, transforming, gradients, fills, outlining, and capturing brushes. The editor uses a mask-based selection — selections can be any shape, not just rectangles, and the boolean modifiers compose them naturally.

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Selection tools

Four ways to make a selection. Each becomes a coloured silhouette outline (purple dashed) on the canvas.

Tool	Hotkey	Behaviour
Rectangle Select	M	Drag from one corner to the opposite. The simplest case.
Magic Wand	W	Click a pixel to select pixels matching its colour. Two modes (see below).
Lasso	Q	Drag a freehand polygon. The selection rasterises on release using even-odd rule.
Selection Brush	A	Paint the selection mask with the active brush size/shape.

Magic Wand modes

Set in Tools panel → Magic Wand options when the tool is active:

• Connected region — flood-fill from the click point. Selects only pixels reachable from the click via 4-connectivity.
• All matching pixels — selects every pixel in the active layer matching the colour, regardless of connectivity.

A Tolerance slider (0–64) adds per-channel ±tolerance to the colour match — useful when you have anti-aliased edges or near-duplicate shades.

Selection Brush — A

A dedicated brush that paints directly into the selection mask — same mental model as the Pencil, but the strokes write into a binary mask instead of pixel colours. Uses your current brush Size and Shape settings.

A single toggle, Constrain to opaque pixels (default on), lives in the Tools panel when the brush is active:

• On — the brush only enrols pixels where the underlying layer has alpha > 0. Painting over the head of a stick figure picks up only the drawn pixels and skips the transparent background.
• Off — every cell the brush touches is enrolled, regardless of layer content.

Modifiers behave the same as the other selection tools: Shift adds to the existing selection, Alt subtracts. The marching-ants overlay grows live with the stroke, so you can see the silhouette form before you release.

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Modifier keys (during drag)

While dragging with Select, Lasso, Magic Wand, or Selection Brush, hold modifiers to compose with the existing selection:

Modifier	Effect
(none)	Replace — discard previous selection
Shift	Add — union of previous and new
Alt	Subtract — remove the new from the previous
Shift+Alt	Intersect — keep only the overlap (rect/lasso/wand only — the brush uses Shift / Alt only)

The combination is a true boolean operation on the masks — works with mixed shapes (e.g. lasso + rect = composite shape).

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Selection actions

Move / floating selection

Drag inside an existing selection with any selection tool (Rect, Lasso, Magic Wand) to lift the pixels into a "floating selection" that follows the cursor. Without modifiers, the gesture always means "move"; holding Shift / Alt routes to the boolean-combine path instead, so the keyboard grammar stays consistent. While floating:

• Arrow keys move it 1 px (Shift+Arrow = 8 px)
• Click outside, or pick another tool, to commit it back into the layer.
• Ctrl+X cuts; Ctrl+C copies; Ctrl+V pastes (the paste appears as a new floating selection).
• Press Shift+T to enter Free Transform with on-canvas handles for live rotate/scale.

Clipboard

Key	Action
Ctrl+C	Copy pixels under the selection (mask-aware — preserves silhouette).
Ctrl+X	Cut — like copy, but clears the underlying pixels.
Ctrl+V	Paste — appears as a floating selection at the original position.
Delete / Backspace	Clear pixels inside the selection without copying.

Select all / deselect / invert

Key	Action
Ctrl+A	Full-canvas rectangle selection
Ctrl+D	Clear the selection
Ctrl+Shift+I	Invert — flip the mask against the canvas, then trim the bounding box

Expand / Contract / Smooth / Border

When a selection is active, the Tools panel shows a Selection section with these operations:

• Expand 1px — 4-neighbour dilate. The mask grows outward by 1 cell.
• Contract 1px — 4-neighbour erode.
• Smooth — morphological open + close (erode→dilate then dilate→erode). Removes 1-px spurs and fills 1-px holes; useful after a noisy Magic Wand pick or freehand Lasso.
• Border… — opens a dialog that replaces the selection with an N-pixel band along its edge. Choose the band thickness and whether it sits Inside, Outside, or Centered on the original mask. Handy for outline-painting workflows that need to fill the band with a colour separately.

These all work on the mask (not the bounding rect), so a lasso selection grows / shrinks / smooths following its silhouette.

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Outline / Stroke selection

Paint the contour of the selection on the active layer. Useful for creating outlines around shapes you've already drawn or selected.

1. Make any selection.
2. Tools panel → Stroke selection button (appears when a non-floating selection is active).
3. Configure in the dialog:
   • Colour — Primary, Secondary, or custom hex
   • Thickness — 1 to 16 px (uses dilate/erode for >1 px)
   • Position — Inside / Outside / Center
4. Click Stroke. One undo entry.

The outline follows the actual mask edges — for a lasso/wand selection, you get a contour that matches the silhouette, not a rectangle.

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Mask-aware overlay

The selection outline you see on canvas (the marching-ants-style dashed line) draws only on cell edges between selected and unselected pixels — so it visually matches the actual mask, not the bounding rect. While dragging a lasso, the overlay renders the live polygon points so you see exactly what will be selected.

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Tips

• A selection persists across tool changes, frame changes, and zoom — until you explicitly clear it (Ctrl+D) or replace it.
• Selections do not persist across save/reload — they're per-session.
• To capture a selection as a custom brush, use Tools panel → Brush → Custom brushes → + Capture.
• Use Ctrl+Shift+I to invert when it's easier to select what you don't want first.

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Related

• Drawing tools — Custom brushes
• Transforms — flip / rotate / free transform respect selections
• Shape tools — Gradient is mask-aware