What's the difference between config fonts in /etc/fonts/conf.d and gnome-tweak-tool?

Question

I can change the hinting and sub-pixel settings from /etc/fonts/conf.d or gnome-tweak-tool. What's the difference of those two methods?

It seems to me that google-chrome and gnome-terminal changes more obviously from /etc/fonts/.

Answer 1

The difference is the two different font configuration systems:

• fontconfig - which allows fine-grained control over font settings, per-font customization etc... via config files like /etc/fonts/conf.d/* or ~/.config/fontconfig/fonts.conf

versus

• XSettings - used by DE (read gtk) and configurable via user-friendly GUI tools (like gsettings, gnome-tweak-tool etc.), with limited configuration options (global settings, i.e. no font specific options)

The choice to follow fontconfig settings or XSettings is implementation specific, e.g. Epiphany - a gtk app based on webkitgtk - when rendering webpages uses fontconfig settings because webkitgtk devs decided to follow fontconfig settings and ignore XSettings.