Topic 03 · Masks & selections

A selection is a stencil.

Open the Mask tab (right panel: Brush · Fx · Mask) — that's where selections live. Once you've selected part of a sprite, everything obeys it: the brush, the fx, move, copy/paste. Paint boldly across the edge and it stays inside the lines. Three things you'll actually use.

A yellow brush stroke painted across a slime but clipped to its silhouette — Brushed right across — but only the pixels inside the selection took the paint.

1Select & move

Make a selection — drag a box, use the Magic wand, or Select same colour. Hold Shift while selecting to add to what's already selected (Alt subtracts) — same as the Replace / Add / Subtract / Intersect buttons at the top of the tab. The wand grabs by colour: raise its tol slider to also catch near-identical shades (size below it sets the freehand mask-brush width).

Then press V (Move / Stretch) and drag inside the selection: it lifts into a floating object you can slide around; drag a corner handle to resize. Click again to drop it. Nothing outside the selection moves.

The slime's body lifted out of its outline and dragged up and to the right

2Clip the brush to the selection

Turn on Enable mask (the mask toggle on the canvas toolbar). Now the brush and every fx only land inside the selection — the status bar reads mask on: brush/fx clipped to mask. Scribble across the whole sprite; the paint only sticks where the mask allows. Great for shading one shape without touching its neighbours.

3Noise mask → tint

The mask doesn't have to be a shape. In the Mask tab, generate a random mask by density — a speckly stencil (tune density and cell size). Then open Fx → Tint and pick a colour: only the speckled pixels take it, giving instant texture — grime, frost, dithered shading. Hit Fx Apply to bake it in.

A random speckled mask over the slime — 1 · random mask by density — a speckly stencil

A blue tint applied only to the speckled masked pixels — 2 · Tint — only the speckled pixels change colour

✓That's the whole idea

Select → the brush, fx, move and clipboard all respect it. New clears the mask when you're done; Mask lock keeps a selection alive through several operations; Invert flips inside for outside.

Copy across frames Copy / Cut / Paste all carry the mask, so you can lift a detail off one frame and drop it on another — handy for fixing a single wobbly frame in an animation.