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Mask Paint

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Mask

Paint masks freehand with a brush. Quick and intuitive for organic selections.

Mask Paint over a street photo: the red car painted into the mask with a soft brush, shown bright while the rest of the street is dimmed, and the brush, eraser and brush settings row above the picture highlighted

The Brush tool (B) paints white, adding to the mask, and the Eraser (E) paints black, removing from it.

Like Paint, it uses the one app-wide current brush, so a textured tip, grain, taper, and pen-pressure dynamics all apply. It has the same Brush Spacing, Flow, Jitter, and Speed Affects Size controls, the same Stabilization, and its own Brushes list with Make Active, Save to Library, Restyle, and Delete per brush. Mask Paint has no color, so clicking a swatch never applies to it. See Brushes.

Both inputs are optional; without either you paint on a blank canvas at the node’s Width and Height. Connect an Image to take its size, see the mask as an overlay on it, and combine with its alpha (“Input Alpha”), or a Mask to combine with it directly (“Input Mask”). Combine Mode appears once either is connected.

Parameters

Section titled “Parameters”

Pins

ImageImage
InputOptional
MaskMask
InputOptional
MaskMask
Output

Output

Width (px)Integer
Default: 1024 Range: 1–8192

Output mask width (locked when image input is connected)

Height (px)Integer
Default: 1024 Range: 1–8192

Output mask height (locked when image input is connected)

Strokes

ToolChoice
Default: Brush Range: Brush / Eraser

Active editing tool (Brush adds, Eraser subtracts)

Brush SizeNumber
Default: 20.0 Range: 1.0–500.0

Brush diameter in pixels

Brush HardnessNumber
Default: 1.00 Range: 0.00–1.00

Edge hardness (0 = soft falloff, 1 = hard edge)

Brush OpacityNumber
Default: 1.00 Range: 0.00–1.00

Stroke opacity per dab

StrokesData

Stroke list (recorded via the canvas manipulator)

Brush SpacingNumber
Default: 0.25 Range: 0.01–2.00

Dab spacing, as a fraction of brush size

Brush FlowNumber
Default: 1.00 Range: 0.00–1.00

Per-dab paint buildup within one stroke (overlapping dabs still cap at Brush Opacity)

Brush JitterNumber
Default: 0.00 Range: 0.00–1.00

Random per-dab positional jitter

Speed Affects SizeToggle
Default: false

Faster strokes place bigger/smaller dabs

Speed->Size MinNumber
Default: 0.50 Range: 0.00–4.00
When Speed Affects Size is on

Dab size multiplier at zero speed

Speed->Size MaxNumber
Default: 1.50 Range: 0.00–4.00
When Speed Affects Size is on

Dab size multiplier at/above the engine's speed reference

Global

OverlayToggle
Default: true

Show the mask as a tinted overlay on the input

Combine ModeChoice
Default: Replace

How painted strokes combine with the input image's alpha

  • ReplacePainted strokes replace the input mask entirely.
  • UnionAdd painted regions to the input mask: white wherever either is white.
  • SubtractRemove painted regions from the input mask.
  • IntersectKeep only the overlap between painted strokes and the input mask.
  • DifferenceKeep non-overlapping areas between painted strokes and the input mask.
InvertToggle
Default: false

Invert the entire mask output

Mask

Mask FromChoice
Default: Luminance
Color image connected to the mask input

How the connected color image is read as a mask

  • LuminanceRead the image's brightness as the mask. The default.
  • AlphaRead the image's transparency as the mask.
  • RedUse the red channel as the mask.
  • GreenUse the green channel as the mask.
  • BlueUse the blue channel as the mask.

Usage Tips

Section titled “Usage Tips”
  • Use a soft brush for feathered selections, and a lower opacity to build up density over several strokes. [ and ] change the brush size; add Shift to change hardness.
  • Wire a mask from another node in and paint on top with Union or Subtract to fix edges that need manual correction.
Section titled “Related Nodes”