Naming reminder. Throughout this page: ShieldFont (CamelCase) is the protocol; ShieldFont Optik is the flagship typeface; a ShieldFont is any base font that has been converted using the protocol. See the introduction for the full naming convention.

A custom mapping and a custom face are two different forks. Custom mappings covers the first: a private dictionary nobody else has. This page covers the second: the typeface your ShieldFont is built on.

You can vary the base typeface independently of the mapping. The protocol is typeface-agnostic: scripts/generate_font.py accepts any base with TrueType outlines (.ttf), so you can build against ShieldFont Optik, ShieldFont Inter, ShieldFont Garamond, or your own studio's typeface. (CFF/.otf fonts are rejected: convert to .ttf first; variable fonts are auto-instanced to their default.) The choice of mapping is what protects your content; the choice of base typeface is purely aesthetic and operational. Forking is the intended mode of use on both axes.

The recipe

scripts/generate_font.py is a one-command builder: point it at a base TTF, give it a name and a mapping, get back a font binary that obeys the protocol:

pip3 install -r requirements.txt

python3 scripts/generate_font.py \
  --base-path /path/to/your-typeface.ttf \
  --name "ShieldFont YourTypeface" \
  --prefix shieldfont-yourtypeface \
  --mapping-path scripts/v18alpha_for_font.json

# Audit the build (optional but recommended):
python3 scripts/audit_font.py --font public/fonts/shieldfont-yourtypeface.ttf \
  --mapping scripts/v18alpha_for_font.json

Outputs land in public/fonts/ as .ttf, .woff2, and a ready @font-face CSS. The --mapping-path argument decides which dictionary the font decodes. The example above uses the shipped alpha pool; to build against a private mapping instead, mint one first and pass its path (see Custom mappings).

The pairing rule from the mappings guide applies unchanged here: a page renders correctly only under a font built from the same mapping that encoded it. Changing the base typeface never changes the pairs; changing the mapping always requires a new font build.

Naming

Recommended naming for community-built ShieldFonts: keep ShieldFont as the prefix, follow with the base typeface name: ShieldFont Inter, ShieldFont Garamond, ShieldFont YourFoundry. Same CamelCase everywhere, including the font's internal name table; context tells you whether the word means the protocol or a specific typeface.

Licensing

The code is AGPL-3.0 (see LICENSE). Font binaries are a separate question, and which terms apply depends on the base typeface you build against. Fonts you generate from an OFL base font (Inter, Syne Mono, Young Serif) are OFL-1.1. The shipped default variants are built on Optik (© Playtype), distributed in ShieldFont's shielded form with Playtype's permission: not OFL, and not for standalone use as a typeface. NOTICE has the details for both cases. Check it before redistributing any font binary.

Custom faces: bring your own typeface

The recipe

Naming

Licensing

See also