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Font System

Source: vignettes/fonts.Rmd
fonts.Rmd

The ggaib package manages fonts automatically so that plots render consistently across machines. When you load the package, it selects the best available font for each of three typographic roles — heading, body, and serif — and tells you what it found.

Font roles

Every theme_aib() variant assigns fonts to plot elements through three roles:

Role Used for Brand font Bundled alternative
heading Plot title, subtitle, facet strips Area Normal Albert Sans
body Axis labels, axis titles, legend Source Sans Pro Source Sans 3
serif Plot caption Minion Pro Crimson Text

Retrieve the active family name for any role with aib_font():

library(ggaib)
#> Brand fonts not found. Using bundled alternatives (Albert Sans, Source Sans 3, Crimson Text).

aib_font("heading")
#> [1] "Albert Sans"
aib_font("body")
#> [1] "Source Sans 3"
aib_font("serif")
#> [1] "Crimson Text"

Or retrieve all three at once:

str(aib_font_families())
#> List of 3
#>  $ heading: chr "Albert Sans"
#>  $ body   : chr "Source Sans 3"
#>  $ serif  : chr "Crimson Text"

How fonts are selected

When the package loads it works through a three-tier priority list for each role:

  1. Brand font — If the preferred font (e.g. Area Normal) is installed on the system, it is used directly.
  2. Bundled alternative — If the brand font is not found, ggaib registers an open-source substitute shipped in the package’s inst/fonts directory using systemfonts::register_font(). Each alternative is bundled in four weights (regular, italic, bold, and bold italic).
  3. System default — If font registration fails entirely (for example, if systemfonts is unavailable), the package falls back to the generic "sans" and "serif" families.

Because the bundled fonts are included in the package itself, the fallback works offline and does not require downloading anything at runtime.

Startup messages

When ggaib is attached it prints a single line indicating which tier is active. The message corresponds to one of four scenarios:

## All brand fonts installed
Using AIB brand fonts (Area Normal, Source Sans Pro, Minion Pro).

## No brand fonts; bundled alternatives registered
Brand fonts not found. Using bundled alternatives (Albert Sans, Source Sans 3, Crimson Text).

## Font registration failed
Font registration failed. Using system defaults (sans/serif).

## Mixed (some brand, some bundled)
Fonts: Area Normal (brand), Source Sans 3 (bundled), Crimson Text (bundled).

If you see the “bundled alternatives” message, plots will still look consistent — the open-source fonts were chosen to be close typographic matches for the brand typefaces.

Graphics device

The font system relies on the systemfonts package to register bundled fonts. For these registered fonts to render correctly, use a graphics device that supports systemfonts, such as the ragg package:

# In an R script
ragg::agg_png("plot.png", width = 7, height = 5, units = "in", res = 300)
print(p)
dev.off()

RStudio and Quarto use ragg by default when it is installed. In an RMarkdown document, set the device in the chunk options:

```{r, dev = "ragg_png"}
```