Advanced LaTeX Font Management: Custom Typography with fontspec, microtype, and unicode-math

Typography lies at the heart of any beautifully crafted document. While LaTeX is celebrated for its default Computer Modern fonts and rock-solid mathematics typesetting, many users crave more expressive, modern, or institution-branded typefaces. Thanks to the power of fontspec, microtype, and unicode-math (in XeLaTeX or LuaLaTeX engines), you can effortlessly tap into your system’s font library, refine spacing and kerning, and achieve professional-grade math face consistency.

In this comprehensive guide, we’ll explore how to select, load, and configure custom fonts in LaTeX; fine-tune your typography with micro-typographic adjustments; and ensure that your mathematical expressions match the style of your body text. Whether you’re preparing an academic journal article, a corporate white paper, or a visually stunning presentation, mastering these tools will elevate your documents to a new level of polish.

1. Why Typography Matters in LaTeX

Good typography goes beyond selecting a pretty font. It encompasses the harmonious interplay of typeface design, spacing, line length, and mathematical consistency. In academic and professional settings, the right typeface can:

• Enhance readability, making dense text more accessible to readers.
• Reflect your brand identity or institutional guidelines.
• Ensure that mathematical symbols blend seamlessly with surrounding text.
• Improve overall aesthetics, impacting how your work is perceived and cited.

While LaTeX’s default Computer Modern is timeless, modern literature often calls for serif, sans-serif, or monospaced fonts beyond the basics. With the emergence of OpenType and TrueType system fonts, it’s never been easier to expand LaTeX’s typographic palette.

2. Getting Started with fontspec

The fontspec package is your gateway to system fonts in XeLaTeX or LuaLaTeX. It provides intuitive commands to select, tweak, and define font families without wrestling with low-level TeX mechanisms.

Basic Usage:

\usepackage{fontspec}
% Load a font by name
\setmainfont{TeX Gyre Termes}
\setsansfont{TeX Gyre Heros}
\setmonofont{Inconsolata}
    

In this example, TeX Gyre Termes serves as a Times-like serif, TeX Gyre Heros as a Helvetica-style sans-serif, and Inconsolata as a programmer’s monospaced font. If your system supports multiple font features (ligatures, alternate glyphs, small caps), you can activate them with options:

\setmainfont[
  Ligatures=TeX,
  SmallCapsFeatures={Letters=SmallCaps},
  Numbers=OldStyle
]{Linux Libertine O}
    

Notice how Ligatures=TeX restores traditional TeX ligature behavior, while Numbers=OldStyle switches to more elegant non-lining numerals. Such fine-grained control can be invaluable for high-end publishing.

3. Fine-Tuning with microtype

While fontspec enables font selection, microtype perfects the spacing. It applies micro-typographic adjustments such as character protrusion (margin kerning) and font expansion, significantly improving justification and optical alignment.

To activate microtype:

\usepackage[protrusion=true,expansion=true]{microtype}
    

By default, microtype loads settings calibrated for Computer Modern. For system fonts, you may need to generate custom configuration files using mtcfgopt (supplied with microtype) or rely on community-provided presets. Many fonts work beautifully out of the box, but for the highest polish, consider:

• protrusion=true: Allows punctuation marks to hang slightly into margins for optical alignment.
• expansion=alltext: Permits subtle font expansion/shrinkage for better justification.
• Custom .cfg files: Define character-specific adjustments for unique glyph shapes.

Well-tuned micro-typography often goes unnoticed—but readers subconsciously appreciate the fluid, professional texture of perfectly justified paragraphs.

4. Math Typesetting with unicode-math

After you select a serif font for body text, you’ll likely want matching math symbols. The unicode-math package brings OpenType math fonts (e.g., Asana Math, Latin Modern Math, STIX Two Math) into your document, ensuring consistency between text and formulas.

Sample configuration:

\usepackage{unicode-math}
\setmathfont{STIX Two Math}
    

With this setup, Greek letters, operators, and specialized symbols adopt the same stroke weight and design language as your main font. You can even mix multiple math fonts:

\setmathfont{XITS Math}[range={up/{latin,Latin,greek,Greek}}]
\setmathfont{Asana Math}[range={\int,\sum,\prod,\coprod}]
    

Splitting ranges allows you to choose the best glyphs from different fonts, crafting a bespoke math palette tailored to your document’s needs.

5. Tips for Choosing and Loading System Fonts

Not all fonts are created equal when it comes to typesetting. Here are some guidelines:

• Serif vs. Sans-Serif: Use serif for body copy in print-style documents; sans-serif excels in slides and informal reports.
• OpenType Features: Look for fonts with robust OpenType support (ligatures, small caps, alternate figures).
• License Compatibility: Confirm that your chosen font’s license permits embedding in PDFs and distribution.
• Font Weight Variants: Ensure availability of multiple weights (light, regular, bold, black) for headings and emphasis.
• Test on multiple platforms: System font names may vary; use fc-list (Linux) or Font Book (macOS) to identify exact names.

When loading, always specify fallback options:

\setmainfont[
  Path = /usr/share/fonts/truetype/libertine/,
  UprightFont = *-Roman,
  BoldFont = *-Bold,
  ItalicFont = *-Italic,
  BoldItalicFont = *-BoldItalic
]{LinuxLibertine}
    

This approach ensures that LaTeX locates the correct font files even in environments where system‐wide font caches differ.

6. Integrating with Your Workflow

To maintain consistency across projects:

• Use a Custom Style File: Create typography.sty to centralize your fontspec, microtype, and unicode-math settings.
• Version Control: Store your style file in Git alongside your manuscript to track changes over time.
• Continuous Integration: Automate PDF builds using GitHub Actions or GitLab CI to ensure that font dependencies are correctly installed in your build environment.
• Document Dependencies: List required fonts and versions in your README to help collaborators replicate your setup.

By systematizing your font management, you minimize “it compiles on my machine” problems and ensure that every collaborator sees the same polished output.