Erase and Fill¶

Two paint-family tools that round out brushwork: Erase (subtractive brushing) and Fill (flood-fill a connected region).

Erase¶

The Erase tool is the inverse of Brush. Same engines, same engine parameters, same dynamics curves; the only difference is the composite mode (write zero alpha instead of accumulating color).

Path	Action
Toolbox > Tools > Erase	Click the icon
Keyboard	`Shift+B` from Brush, or `Shift+B` from anywhere

Shift+B toggles between Brush and Erase. Hold B to enter the Quick Wheel even from Erase; the picked engine becomes the active Brush engine and toggling restores the matching Erase engine.

Erasing with a hard Round Stamp leaves crisp gaps; erasing with the Airbrush feathers them; erasing with Wet Mix softens edges toward the underlying color (great for reducing oversaturation without going to gray). The shared engine surface keeps the mechanics identical so users do not learn twice.

Hardness and pressure¶

A pressure-sensitive Erase respects the same pressure → opacity curve as Brush. Light press leaves faint traces of the underlying paint; full press deletes to fully transparent.

Erase only on the active layer¶

Erase, by default, only affects the active layer. Toggle "All layers" in the Tool Properties dock to erase through every layer.

Fill¶

Flood-fill the connected region the cursor is over. Picks up the target color from the current pixel and replaces every adjacent pixel matching the source within a configurable tolerance.

Path	Action
Toolbox > Tools > Fill	Click the icon
Keyboard	`G`

Tolerance¶

The Tool Properties dock shows the tolerance slider (0 - 1.0). 0 means "only exactly this color"; 1.0 means "everything connected". Most fills work well at 0.05 - 0.15.

Anti-alias¶

For soft-edged fills (where the boundary is a gradient, not a hard line), enable Anti-alias fill in the dock. The flood ramps opacity at the boundary instead of hard-clipping.

Sample mode¶

Mode	Source pixel
Active Layer	The clicked layer's pixel (default)
All Layers	The composited pixel from every layer above + below
Mask Only	The mask alpha (paints into mask, ignores RGB)

Fill with Mask Only is the right mode when authoring a render-part mask by clicking inside the desired region.

Contiguous¶

Contiguous: on (default) fills only the touching region. Contiguous: off fills every pixel that matches the source color on the entire layer: useful for swapping a single color across the whole canvas.

Common patterns¶

Erase the soft edge after Airbrush¶

After overshoot on an Airbrush stroke, switch to a Round Stamp Erase at low opacity to clean up the soft halo without nuking the core color.

Fill the body, then paint the wings¶

For a Monarch-style butterfly: Fill with Mask Only + Contiguous to mask the body region, then paint only the wings: paint outside the mask is ignored.

Replace a single color across the canvas¶

Set Contiguous off, click anywhere in the source color, and Fill swaps every matching pixel to the new color. Faster than re-painting.