Save PDFs with custom fonts"
In camcorder: Record Your Plot History

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  warning = FALSE,
  message = FALSE
)

{camcorder} doesn't only work with raster images such as PNG and JPEG but also PDF files. There are some benefits of using the PDF format when saving ggplot output: vector graphics are lossless, can be converted easily in raster formats of any resolution and also be manipulated afterwards in a vector design tool. Furthermore, the PDF format often supports the use of custom fonts (when using the Cairo device)[^f1].

[^f1]: Thanks to the {ragg} package custom font support is working quite well for raster images now—but it's not a vector graphic 🙃

To automatically save your graphics in PDF format, just change the device setting to cairo_pdf[^f2] when recording your ggplot code:

[^f2]: Cairo is an open-source graphics library that is known to work very well with custom fonts.

library(ggplot2)
library(camcorder)

gg_record(
  dir = file.path(tempdir(), "recording"), 
  device = cairo_pdf, # we need to set the Cairo device
  width = 8,
  height = 5
)

Mac users should ensure that XQuartz is installed which is needed to use the cairo pdf device.

To supply custom fonts in R, the respective font needs to be installed locally on the system.

You can make sure the font file is installed by using the system_fonts() from the latest standard, the {systemfont} package:

systemfonts::system_fonts()

You can simply filter this tibble for any font:[^f3]

[^f3]: To make the difference obvious we use the fun, quirky font DynaPuff which is freely available.

systemfonts::system_fonts() |> 
  dplyr::filter(grepl("Dyna", family)) |>
  dplyr::pull(name) |> 
  sort()

Now let's create a graphic with the DynaPuff Condensed typeface as the base_family of our theme:

g <- 
  ggplot(diamonds, aes(x = cut)) + 
  geom_bar(fill = "grey65") +
  theme_minimal(
    base_family = "DynaPuff Condensed",
    base_size = 24
  )

g

And now let's add a non-condensed, bold title:

g +
  ggtitle("PDFs are a font lovers best friend") +
  theme(
    plot.title.position = "plot",
    plot.title = element_text(family = "DynaPuff", face = "bold")
  )