For each character:
- Export as SVG.
- Open SVG in Inkscape.
- Export PNG image at 600 DPI.
- Add layer mask (white). (gimp-layer-add-mask)
- Select layer mask. (gimp-layer-set-edit-mask)
- Filters→Render→Noise→Plasma… Turbulence 4.5. (plug-in-plasma)†
- Adjust Brightness and Contrast. Brightness 50. Contrast 127. (gimp-brightness-contrast)
- Apply layer mask. (gimp-layer-remove-mask, MASK-APPLY)
- Alpha to selection. (gimp-image-select-item)
- Select→Distort… Threshold 127, Spread 12, Granularity 12, Smooth 1. (script-fu-distress-selection)
- New layer. (gimp-image-add-layer)
- Delete old layer. (gimp-image-remove-layer)
- Bucket fill selection. (gimp-edit-bucket-fill)
- Export to PNG. (file-png-save-defaults)
- Re-import to FontForge.
- Auto trace, ignore white, default settings.
† Random seed should be of sequence 11, 22, 33, 44 … 99, 111, 222, 333, 444, … 999, 1111.
Two example glyph generated using the Style A formula with differing seeds (11, 22).
Input:
Output: