Creating Custom Brushes in GIMP

Brush File Formats

GIMP uses three brush file formats. Understanding the difference between them determines what type of brush you create and what workflow you follow. Custom brushes are especially valuable in portrait retouching, where textured and healing brushes do work that standard round tips cannot.

Creating a Simple Brush from a Shape

Any GIMP image or selection can become a brush tip. The simplest method uses greyscale: white areas are transparent, black areas are fully opaque, and mid-tones are partially transparent.

1. 1
   Create a new canvas: File → New. Size: 200 x 200 px (or any size). Set fill to White (not transparent - Brush tips use greyscale, not alpha). Click OK.
2. 2
   Draw your brush shape: Paint, draw, or stamp your shape in black. Examples: a leaf shape drawn with the Paths tool, a splatter made with a textured brush, a star drawn with the Script-Fu star function, or a cracked texture created with the Plasma + Emboss workflow.
3. 3
   Ensure greyscale mode: Image → Mode → Greyscale. The .gbr format stores greyscale data. The actual color when painting is taken from the foreground color at the time of use.
4. 4
   Export as .gbr: File → Export As. In the file type field, select "GIMP Brush (.gbr)". In the export dialog, enter a brush description and set the spacing (10–25 is typical). Click Export.
5. 5
   Copy to brush folder and refresh: Copy the .gbr file to your GIMP brushes folder. In GIMP, open the Brushes dialog (Windows → Dockable Dialogs → Brushes) and click the refresh button (circular arrow). The new brush appears in the list immediately.

Creating a Brush from a Photo or Texture

Photo-based brushes (leaves, feathers, cracked paint, fabric) are created by photographing or scanning the subject, then converting the result to a high-contrast greyscale image suitable for use as a brush tip.

1. 1
   Open your source image.
2. 2
   Isolate the subject: Use the Scissors tool, Foreground Select, or fuzzy select to isolate the subject. For photographed subjects on a white background (e.g. ink-stamped leaves), use Colors → Levels to push white to pure white and dark areas toward black.
3. 3
   Convert to greyscale: Image → Mode → Greyscale. Colors → Levels or Curves to ensure a clean black-on-white result - No grey fringes.
4. 4
   Scale to a suitable size: Image → Scale Image. Brush tips above 1000 px consume memory and slow down painting. 200–500 px is ideal for most uses. Scale in GIMP using cubic interpolation (Image → Scale Image → Interpolation: Cubic).
5. 5
   Export as .gbr: File → Export As → .gbr. Set spacing to 30–60 for photo brushes used with jitter/scattering.

Brush Spacing and Jitter Settings

After selecting a brush, the Tool Options panel (for Paintbrush, Pencil, or Airbrush) exposes spacing, jitter, and dynamics settings that transform a simple brush tip into a natural, organic mark.

Creating an Animated Brush Tip (.gih) for Natural Media

A .gih (GIMP Image Hose) brush contains multiple brush tips that are cycled, randomized, or selected based on pressure or angle as you paint. This mimics the variation of a real brush or leaf stamp - No two dabs look identical.

1. 1
   Create multiple brush tip variations: Create 4–8 versions of your brush shape, each slightly different (rotated, slightly scaled, slightly distorted). Each becomes one "frame" in the image hose. Keep them all the same pixel dimensions.
2. 2
   Create a multi-layer GIMP file: In a single .xcf file, create one layer per brush variation. Name each layer clearly. The canvas size should be the same as each brush tip. This multi-layer file is the source for the .gih export.
3. 3
   Export as .gih: File → Export As → GIMP Image Hose (.gih). In the export dialog: set Spacing (e.g. 80%), Cell width and Cell height (should match each layer's dimensions), Number of cells (number of layers), and Selection mode (Random for natural variation, Incremental to cycle in order, Angular or Pressure to tie to input).
4. 4
   Copy to brushes folder and refresh.
5. 5
   Test the brush: Select the .gih brush in the Brushes dialog. Paint a stroke - Each dab should use a different variation from your brush tip set, selected according to the mode you specified.

Installing Brushes (Copy, Refresh, Use)

1. 1
   Find your brush folder: Edit → Preferences → Folders → Brushes. The path listed first is your user brush folder.
2. 2
   Copy the brush files: Place .gbr, .gih, or .abr files directly in the brushes folder. You can create sub-folders to organise by category - GIMP displays them in folder groups in the Brushes dialog.
3. 3
   Refresh without restarting: In the Brushes dialog, click the refresh button (circular arrow at the bottom). New brushes appear immediately. Alternatively, Script-Fu: (gimp-brushes-refresh).

Converting Photoshop ABR Brushes

GIMP 3.x can read Photoshop ABR brush files directly - Simply copy the .abr file to your GIMP brushes folder and refresh. GIMP reads ABR versions 1 through 6 (created by Photoshop CS up to CS6 and beyond).

• ABR files with computed/parametric brush shapes (circular tips with dynamic parameters) are supported. GIMP interprets them as static rasterized tips.
• ABR files containing sampled (rasterized) brush tips work perfectly in GIMP.
• Photoshop brush dynamics (pressure mapping, taper, scatter set in Photoshop) are not transferred - You must re-configure dynamics within GIMP's Dynamics Editor for the imported tips.
• If an ABR file does not appear after refreshing, try renaming the extension to lowercase (.abr not .ABR) on case-sensitive filesystems (Linux).

Brush Packs Worth Downloading

These sources offer high-quality free brushes in GIMP-compatible formats (.gbr, .gih, or .abr):

Managing and Organising Your Brush Library

A large, unorganised brush library slows you down. Use sub-folders within the GIMP brushes directory to group brushes by type. GIMP displays each subfolder as a collapsible group in the Brushes dialog.

• Suggested folder structure: brushes/01-basic/, brushes/02-texture/, brushes/03-organic/, brushes/04-effects/, brushes/05-stamps/. Numeric prefixes control display order.
• Tag brushes: GIMP 3.x supports tagging brushes from within the Brushes dialog. Right-click a brush → Add Tag. Tags allow filtering by keyword regardless of folder structure.
• Delete unused brushes: Brushes you never use add clutter and slow down brush panel loading. Move brushes you rarely use to an "archive" sub-folder outside the active brushes path.
• Back up your brushes folder: Include the GIMP brushes folder in your regular backup. A custom brush library represents significant creative investment and cannot be restored from GIMP alone if lost.
• Script-Fu list: In the Script-Fu Console, (gimp-brush-get-info "brush-name") returns size and spacing metadata for any loaded brush. Useful for auditing your library programmatically.