Bastardica mixes typefaces into downloadable OpenType fonts
The browser-based tool uses contextual substitutions to combine glyphs from source fonts, with processing run locally on the user’s device.
Bastardica is a browser-based tool for creating “bastard” fonts: downloadable OpenType files that mix glyphs from selected source fonts. The project was surfaced in a Hacker News post on 23 September.
The tool uses contextual substitutions to swap glyphs. Its site says the feature is registered for every script and enabled by default in apps that shape OpenType text, including browsers, design tools and print workflows. If a generated font looks unchanged, the site advises checking whether ligatures are switched off in the app.
Font generation runs locally in the browser using Pyodide and fontTools, according to the site. Users can also apply vertical offset and scaling effects to align glyphs.
When combining three or more fonts, some glyph selections can overlap. Bastardica says the first font takes precedence in a collision and recommends prime-number strides to make overlaps less frequent.
The site says the project was inspired by Times New Bastard and Easy Pete. It advises users to check the licences of source fonts before commercial use, noting that combining two fonts produces a derivative work. Bastardica says it adds no conditions of its own.
