Technical aspects
A brush has two parts: the stamp, the shape that gets stamped, and the modifier, which decides how it is stamped. Here are the sizes and formats it needs.
The stamp: the shape
The stamp is the shape that repeats along the stroke, added in three ways:
- Import an image: drop a PNG on the Stamps box.
- Create stamp: draw the shape in a 512×512 px area. Black turns opaque, white transparent.
- Use current page: capture what you painted on the page.
A stamp gives you an image brush, which uses your image as its shape, or a procedural brush, which builds the shape from rules.
Size and format
Ideally a square PNG of 256×256 or 512×512 pixels with a transparency channel.
- Without a transparency channel, transparent areas blend into the drawing and the brush stamps solid rectangles.
- The file picker offers .png and .webp; dragging a file onto the box accepts a JPG.
- If the image is larger, RobinPad does not shrink it: a bigger image gives you a heavier brush, not a better one.
- Black and white or gray tones only: black and gray draw the shape. A color image is converted automatically.
The modifier
Each modifier changes one thing about the stroke, and you notice it while painting:
- Spacing: distance between stamps along the stroke.
- Flow: how much color each stamp leaves.
- Min size and Max size: the size range of the brush.
- Pressure → Size, Pressure → Opacity and Pressure → Rotation: how much the brush changes with pressure.
- Rotation: Mode, Angle, Random jitter and Pressure influence.
- Scatter: pulls stamps away from the center. Splatter: adds loose dots.
- Mirror and Distort: flip or narrow the stamp as you paint.
Test and save
A Live preview on the side runs the brush in a loop. The pack is saved as a .rbrush file.