Subtractor

Effect plug-in for the Glyphs.app font editor for subtracting prebuilt shapes from your glyph layers.

Installation

1. One-click install Subtractor from Window > Plugin Manager
2. Restart Glyphs.

Usage

The filter boolean-subtracts shapes from the affected glyph layers. The shapes come from special glyphs in your font named _subtract, or with a dot suffix such as _subtract.rough or _subtract.edge. If multiple subtract glyphs are present, one is chosen at random each time the filter is applied, creating natural variation across glyphs.

Preparing subtract glyphs

1. Add a glyph named _subtract (or _subtract.xxx with a dot suffix) to your font.
2. Draw the shapes you want to subtract from your glyphs in that special glyph.
3. Apply Filter > Subtractor to the glyph layers you want to process.

Settings

• Subtract Shapes: Name prefix of the subtract glyphs in your font. Default: _subtract. Change this if you want to use a different set of shapes for different effects.
• Random Rotate: Maximum rotation angle in degrees. The subtract shape is rotated by a random amount between −n° and +n° around its bounding-box centre before subtracting. Default: 5.
• Random Offset: Maximum displacement in font units. The subtract shape is shifted by a random amount up to ±n units in both X and Y before subtracting. Default: 20.

Notes

• Multiple subtract glyphs: If several glyphs match the prefix (e.g., _subtract, _subtract.variant1, _subtract.rough), one is picked at random on each application for natural variation.
• Components: Components inside _subtract glyphs are automatically decomposed before the subtraction.
• Masters: The layer matching the current master is used. If no matching master layer exists, the first available layer is used as a fallback.

You can also add the filter as a custom parameter to one of your (static) instances in Font Info > Exports. Use the actions menu in the lower left to copy the current settings as a custom parameter into the clipboard, then paste it in Font Info.

When applied as a custom parameter (during batch export), the following glyphs are always excluded from processing:

• All glyphs whose name starts with the Subtract Shapes prefix
• .notdef
• The Apple glyph (uniF8FF), which many foundries use for their own logo
• Empty glyphs (no outlines or components on the layer)

Keep in mind that boolean operations are CPU-intensive, so exporting a whole font with this effect may take some time.

License

Copyright 2024–2026 Rainer Erich Scheichelbauer (@mekkablue).

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

See the License file included in this repository for further details.