How to Use the Paintbrush in GIMP

The Paintbrush is GIMP's main freehand drawing tool. Whether you are retouching photos, painting digital art, or just masking a layer, most brush work happens here. Once you know how to control size, hardness, and opacity, you will be able to do a lot with it.

Activating the Paintbrush

Press P to activate the Paintbrush. The cursor changes to a circle representing the brush tip.

The Paintbrush paints with the current foreground color (the top color square in the toolbox). Click the foreground color swatch to change it. Press D to reset to black/white defaults, X to swap foreground and background.

Setting Brush Size and Hardness

In the Tool Options panel with the Paintbrush active:

• Size: Drag the Size slider or type a pixel value. Larger = bigger strokes. You can also change size directly on the canvas with the [ and ] keys.
• Hardness: Controls how sharp or soft the brush edge is. 100% hardness = crisp pixel edges. 0% = very soft feathered edge. Most retouching and masking work uses 0-50% hardness for natural blending.
• Aspect ratio: Default is circular. Change it to create oval or angled brush tips.

Quick adjustment: right-click while the Paintbrush is active to open a mini brush editor popup directly on the canvas. You can change size and hardness there without going to Tool Options.

Opacity and Flow

Two settings control how much paint is applied per stroke:

• Opacity: How transparent each stroke is. At 100%, fully opaque. At 50%, semi-transparent. Multiple strokes at 50% build up toward full opacity if you keep painting over the same area.
• Flow (or "Rate" in some versions): How fast paint builds up while you hold the mouse button. Low flow with a stylus gives a more watercolor-like effect.

For clean, precise work (like painting on layer masks), use 100% opacity and 100% flow. For artistic brush strokes and photo retouching, lower opacity (30-70%) gives more control.

Choosing a Brush Preset

GIMP comes with dozens of brush presets. In Tool Options, click the brush thumbnail to open the Brush picker. You will see:

• Round brushes: Most common. Smooth edges at various sizes.
• Hard brushes: Sharp pixel-level edges.
• Textured brushes: Simulate canvas, chalk, or bristle textures.
• Artistic brushes: Complex shapes for decorative effects.

For most work, the basic round brush (2. Hardness 100 or 2. Hardness 025) is the right starting point. Use a hard round for precise work, a soft round for retouching and masking. Custom brushes can be added the same way fonts are added - drop the .gbr file into the brushes folder in GIMP's data directory.

Essential Shortcuts