Readerly

Readerly is modified font based on Newsreader, while attempting to be metrically very similar to Bookerly, the default font on Kindle devices, to provide a similar reading experience.

When I was doing my usual font tweaking for my ebook-fonts repository, I stumbled upon variable fonts exporting. Doing this for Newsreader gave me some interesting results at small optical sizes: the font was now reminding me of Bookerly.

I asked myself the question: how close can we get to the metrics of Bookerly while still retaining Newsreader and keeping the font licensed under the OFL, and maybe making some mild manual edits?

The goal was to get a metrically/visually similar font, without actually copying glyphs or anything that would infringe upon the rights of the original creators; after all, Newsreader is a very beautiful font as a starting point.

To get to the final result, I decided to use the variable font and work on it. The original is located in src and is available under the same OFL as the end result, which is included in LICENSE.

Downloads

Two versions are generated via the pipeline of the latest release:

• KF_Readerly.zip — Kobo-optimized TrueType fonts with a legacy kern table and KF prefix. Use this if you have a Kobo e-reader, this version contains optimizations made with Kobo Font Fix.
• Readerly.zip — The standard, unmodified fonts, as TrueType files. Useful for other e-readers and use on your desktop computer or smartphone.

Project structure

• src: Newsreader variable font TTFs
• build.py: The build script to generate Readerly
• LICENSE: The OFL license
• COPYRIGHT: Copyright information, later embedded in font
• VERSION: The version number, later embedded in font

After running build.py, you should get:

• out/ttf: final TTF fonts (generated)

Prerequisites

• Python 3
• fontTools — install with pip install fonttools
• FontForge — the build script auto-detects FontForge from PATH, Flatpak, or the macOS app bundle
• ttfautohint — required for proper rendering on Kobo e-readers

Linux preparation

sudo apt install ttfautohint        # Debian/Ubuntu
sudo dnf install ttfautohint        # Fedora
brew install ttfautohint            # Bazzite (immutable Fedora)
pip install fonttools
flatpak install flathub org.fontforge.FontForge

macOS preparation

System Python

On macOS, if you're using the built-in version of Python (via Xcode), you may need to first add a folder to your PATH to make font-line available, like:

echo 'export PATH="$HOME/Library/Python/3.9/bin:$PATH"' >> ~/.zshrc
brew install fontforge ttfautohint
brew unlink python3 # ensure that python3 isn't linked via Homebrew
pip3 install fonttools font-line
source ~/.zshrc

Homebrew Python

If you're using brew install python, pip requires a virtual environment:

brew install fontforge ttfautohint
python3 -m venv .venv
source .venv/bin/activate
pip install fonttools

Building

Note: If you're using venv, you will need to activate it first:

source .venv/bin/activate

If you are just using the system Python, you can skip that step and simply run:

python3 build.py

To customize the font family name, disable old-style kerning, or skip outline fixes:

python3 build.py --customize

The build script (build.py) uses fontTools and FontForge to transform the Newsreader variable fonts into Readerly. After export, it post-processes the TTFs: clamping x-height overshoots that cause uneven rendering on e-ink, normalizing style flags, and autohinting with ttfautohint for Kobo's FreeType renderer. Configuration and step-by-step details live in the header comments of build.py.