// Personal website of Chris Smith

Some lighter fonts are barely readable on lower contrast backgrounds, and some web designers like to err on the side of stupidly light fonts. To prevent Firefox from using these, create a new fontconfig file in e.g. ~/.config/fontconfig/firefox.conf containing:

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
	<include>fonts.conf</include>
	<selectfont>
		<rejectfont>
			<glob>*/DejaVuSans-ExtraLight.ttf</glob>
		</rejectfont>
	</selectfont>
	<selectfont>
		<rejectfont>
			<glob>*/Inconsolata-ExtraLight.ttf</glob>
		</rejectfont>
	</selectfont>
	<selectfont>
		<rejectfont>
			<glob>*/Inconsolata-Light.ttf</glob>
		</rejectfont>
	</selectfont>	
</fontconfig>

Then start Firefox with the FONTCONFIG_FILE=~/.config/fontconfig/firefox.conf environment variable set (e.g. by adding it to the desktop entry)