Numderline

Numderline is a hacky font patcher that takes a font and converts it into one that underlines alternating groups of 3 digits starting from the right. It can also do other similar tricks.

It was inspired by my job involving a lot of staring at numbers in nanoseconds and trying to pick out the milliseconds or microseconds.

A blog post about this and a web page to see and download pre-patched fonts should hopefully be coming soon™.

Features

• Patch any font to underline alternating groups of 3 digits in numbers
• For use in proportional contexts, can also just insert fake commas with shaping
• Alternatively it can squish digits and group them closer together in threes
• Or some other variants, including small monospace mini-commas!

Usage

1. Clone the repo
2. Install the FontForge Python API, on macOS I used Homebrew to do this with brew install fontforge, or you can use brew bundle
3. Install the fonttools API, I used pip3 install fonttools to install it in my Homebrew python3, or you can use pip3 install -r requirements.txt
4. Run python3 patcher.py FONT_FILE_TO_PATCH and look in the out folder

You can also run python3 patcher.py --help and read the source to see other options.