Typus Mono

Typus Mono is a custom-compiled, condensed, and strictly ligature-free programming font family derived from JetBrains Mono Nerd Font.

It serves as my personal daily driver. I maintain this repository as a central, easily accessible storage for my setups, though others who share my exact aesthetic preferences and layout constraints may find it useful.

Motivation

My journey with terminal aesthetics reached its peak with a highly tuned configuration in the Ghostty terminal emulator. By using cell compression (adjust-cell-width = -1 and adjust-cell-height = 1 at a size of 12pt), I achieved a compact, high-information-density monospace grid that felt incredibly crisp to my eyes.

However, when using GNU Emacs I faced a major obstacle. While terminal emulators can dynamically pack cells tighter by shifting rendering coordinates, Emacs GUI relies on the font's native metrics. It has no built-in mechanism for sub-pixel character width compression yet (maybe someday?).

To dissolve this mismatch and bring the exact, beloved Ghostty text layout into Emacs GUI, the modifications had to be baked directly into the font files. Thus, Typus Mono was born.

Engineering Details

To achieve a pixel-perfect layout duplicate without ruining legibility, the customization relies on two key modifications:

1. Spacing-Only Metrics Compression (90%, 92%, and 95% Widths)

A naive approach would simply scale the font coordinates horizontally. However, horizontal scaling distorts the glyph vectors, turning round shapes into ugly ovals and breaking subpixel hints.

Typus Mono preserves the glyph outlines 100% untouched. Instead, it scales only the horizontal advance metrics (hmtx table) down to 90%, 92%, or 95%. The characters keep their original, beautifully designed proportions but are packed closer together - exactly mirroring Ghostty's cell width adjustment.

2. Shifted Weight Mapping (Compensating for FreeType)

When comparing GUI Emacs with Ghostty, my eyes immediately noticed a weight discrepancy. GPU-accelerated terminal renderers (such as Ghostty's custom shaders) naturally draw text with slightly more visual weight ("density"). Emacs GUI, using standard FreeType rasterization on Linux, renders the exact same font files noticeably thinner.

To correct this and restore visual parity, the font files were shifted up by weight classes:

• Typus Mono Regular is built from original SemiBold.
• Typus Mono SemiBold is built from original Bold.
• Typus Mono Bold is built from original ExtraBold.
• Typus Mono Light is built from original Regular.
• Typus Mono Thin is built from original Light.

This weight compensation, combined with the metrics scaling, yields a 1:1 pixel-perfect match between Ghostty and Emacs GUI (measuring exactly 574 pixels for 64 characters at size 12 with the 95 spacing variant).

3. Strict Ligature Stripping

Contextual alternates (calt), standard ligatures (liga), discretionary ligatures (dlig), and contextual ligatures (clig) are disabled directly inside the OpenType GSUB table. I don't really like them and this guarantees a clean, distraction-free environment without programming ligatures across all applications.

Included Styles

Each scaling factor (90, 92, and 95) has its own independent family containing 12 styles:

• Typus Mono 90: TypusMono90-Thin.ttf, TypusMono90-ThinItalic.ttf, TypusMono90-Light.ttf, TypusMono90-LightItalic.ttf, TypusMono90-Regular.ttf, TypusMono90-Italic.ttf, TypusMono90-SemiBold.ttf, TypusMono90-SemiBoldItalic.ttf, TypusMono90-Demibold.ttf, TypusMono90-DemiboldItalic.ttf, TypusMono90-Bold.ttf, TypusMono90-BoldItalic.ttf
• Typus Mono 92: TypusMono92-Thin.ttf, TypusMono92-ThinItalic.ttf, TypusMono92-Light.ttf, TypusMono92-LightItalic.ttf, TypusMono92-Regular.ttf, TypusMono92-Italic.ttf, TypusMono92-SemiBold.ttf, TypusMono92-SemiBoldItalic.ttf, TypusMono92-Demibold.ttf, TypusMono92-DemiboldItalic.ttf, TypusMono92-Bold.ttf, TypusMono92-BoldItalic.ttf
• Typus Mono 95: TypusMono95-Thin.ttf, TypusMono95-ThinItalic.ttf, TypusMono95-Light.ttf, TypusMono95-LightItalic.ttf, TypusMono95-Regular.ttf, TypusMono95-Italic.ttf, TypusMono95-SemiBold.ttf, TypusMono95-SemiBoldItalic.ttf, TypusMono95-Demibold.ttf, TypusMono95-DemiboldItalic.ttf, TypusMono95-Bold.ttf, TypusMono95-BoldItalic.ttf

Building from Source

The repository contains the exact tools used to build this font family. If you have Python and fonttools installed, you can re-run the build:

# Searches standard paths for source JetBrainsMono Nerd Font files and builds all variants
./build.sh

You can pass a custom source directory path if needed:

./build.sh /path/to/source/jetbrains-mono-nerd-font/directory

Installation

mkdir -p ~/.local/share/fonts/TypusMono
cp fonts/*.ttf ~/.local/share/fonts/TypusMono/
fc-cache -fv

To load one of the families (e.g., Typus Mono 95) in Emacs GUI:

(set-frame-font "Typus Mono 95-12:weight=normal" nil t)

License & Credits

Typus Mono is licensed under the SIL Open Font License, Version 1.1 (OFL).

• Derived from JetBrains Mono (Copyright (c) 2020, JetBrains).
• Nerd Font glyphs integrated from Nerd Fonts.