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Fonts

Source: vignettes/fonts.Rmd
fonts.Rmd

arframe uses fonts that align with FDA and EMA submission guidance. This vignette covers the default font, the resolution order when a font isn’t available, and how to override it.

Default font

The package default is Times New Roman at 9 pt — the FDA-recommended serif font for submission documents. This applies to all backends: RTF, PDF, and HTML.

# inst/defaults/_arframe.yml (shipped with arframe)
page:
  font_family: "Times New Roman"
  font_size: 9

Font resolution order

When arframe needs a font, it checks availability in this order:

Priority Serif (roman) Sans-serif (swiss) Monospace (modern)
1. FDA-recommended Times New Roman Calibri / Arial Courier New
2. ARFRAME_FONT_DIR (user-supplied) (user-supplied) (user-supplied)
3. Adobe open-source Source Serif 4 Source Sans 3 Source Code Pro
4. CSS generic serif sans-serif monospace

Priority 1 covers Windows and macOS out of the box. On bare Linux/Docker, these Microsoft fonts are typically absent, so arframe moves to the next tier.

Priority 2 checks the directory pointed to by the ARFRAME_FONT_DIR environment variable. Place .ttf or .otf files there and arframe will find them — no system-wide installation needed. This is the recommended approach for Docker, CI, and reproducible environments:

export ARFRAME_FONT_DIR="/opt/fonts"
# Place SourceSerif4-Regular.ttf etc. in /opt/fonts/

Priority 3 uses the Adobe Source font family (SIL Open Font License 1.1). These are free, high-quality, and designed to pair together. Install them from:

Priority 4 (HTML only) is the CSS generic family keyword. RTF/PDF viewers will substitute the closest available system font.

Three font families

arframe classifies every font into one of three families. Each family maps to the correct AFM metrics (for auto-width columns), RTF family keyword, and LaTeX font command:

Family Recognised fonts AFM metrics
roman (serif) Times New Roman, Source Serif 4, Georgia, Palatino, Cambria, Noto Serif Times-Roman
swiss (sans-serif) Calibri, Arial, Helvetica, Source Sans 3, Verdana, Tahoma, Segoe UI, Noto Sans Helvetica
modern (monospace) Courier New, Source Code Pro, Consolas Courier

Unknown fonts default to the monospace family.

Changing the font

Per-table 

spec <- tbl_demog |>
  fr_table() |>
  fr_page(font_family = "Calibri", font_size = 10)

Session-wide (theme) 

fr_theme(font_family = "Arial", font_size = 10)
# All subsequent fr_table() calls use Arial 10pt

Project-wide (config file)

Place an _arframe.yml at your project root:

page:
  font_family: "Source Sans 3"
  font_size: 10

Precedence

Package defaults < _arframe.yml < fr_theme() < fr_page().

Monospace for listings

Courier New remains the standard for code listings where column alignment matters. Use fr_page(font_family = "Courier New") for listing outputs:

spec <- listing_data |>
  fr_table() |>
  fr_page(font_family = "Courier New", font_size = 8)

FDA guidance summary

Element Recommendation
Narrative text Times New Roman or Calibri, 12 pt
Table body 9–10 pt (arframe default: 9 pt)
Footnotes 9–10 pt
Font colour Black only; blue for hyperlinks

Source: FDA PDF Specifications, ICH E3 Structure and Content of Clinical Study Reports.