/etc/fonts/conf.avail/10-hinting-slight.conf is in fontconfig-config 2.11.94-0ubuntu1.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | <?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<!-- Use Slight Hinting -->
<match target="font">
<edit name="hintstyle" mode="assign"><const>hintslight</const></edit>
</match>
</fontconfig>
|