I just installed KDE 4.2 a couple days ago with everything running great but when I went to change the panel font today I noticed that the fonts to choose from were beginning to blur. This wasn’t like this a couple days ago. Then I started up Firefox and the fonts were really blurry, like headache blurry. I renamed all my kde configuration folders and logged in again to no effect. Then I deleted all of KDE temp files first in /tmp and then in /var/temp and I couldn’t get it fixed. Finally I discovered this was from an overwritten ~/.fonts.conf file, fontconfig eventually adding options it previously hadn’t. To cut to the quick, I learned how to configure fontconfig and even learned howto enable fontconfig system-wide and now my fonts look great. Fontconfig works great if you keep it basic, so I’ve updated my post on Better LCD Font Rendering. Enjoy.