SUMMARY Changing fonts in KDE System Settings will force hinting to true in .fonts.conf when desired result is false. Likely regression of https://bugs.kde.org/show_bug.cgi?id=105797 STEPS TO REPRODUCE 1. Have hinting manually set to "false" in .fonts.conf 2. Change fonts in KDE System Settings OBSERVED RESULT .fonts.conf now displays "true" for hinting. EXPECTED RESULT .fonts.conf to stay as "false" for hinting if I manually defined it in the file. SOFTWARE/OS VERSIONS Operating System: SteamOS 3.4.11 KDE Plasma Version: 5.26.1 KDE Frameworks Version: 5.99.0 Qt Version: 5.15.6 Kernel Version: 5.13.0-valve37-1-neptune (64-bit) Graphics Platform: X11 ADDITIONAL INFORMATION With the fonts I generally use and with a certain amount of understanding of how Freetype (and also the associated QT bug of always forcing AA except in some apps/areas) works, I get the best text rendering results with: hinting false, hintstyle hintfull, rgba rgb, antialias false. These 4 settings will render well like on Windows. Using hinting true will make the fonts look worse with the remaining 3 declarations. This is why I prefer hinting false.
Thank you for the bug report! Please note that Plasma 5.26.1 will not be supported for much longer by KDE; supported versions are 5.27, and 5.27 or newer. Please upgrade to the latest version as soon as your distribution makes it available to you. Plasma is a fast-moving project, and bugs in one version are often fixed in the next one.
You can turn hinting off on the fonts page too, but it's true that its default setting doesn't respect what's set systemwide.