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I am experiencing an issue with font rendering issue in GTK based applications (for example; Firefox, GIMP).

I've read a bunch of Google answers about this, but haven't figured out yet what to do. It is clear that something is wrong with the GTK theme, but what?

As you can see from the below screenshot of Firefox, both the text on the page and the menu characters are rendering incorrectly:

bad rendering

Any ideas on how to resolve this issue?

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The problem is: KDE has no support to "demi bold" (or semi bold) fonts, while GTK yes.

I was using a font that has a "demi bold" option, which was translated by KDE to bold.

This appears to be fixed since version 4.8, but not an option for Kubuntu users (mainly if you're using 12.04 LTS, as me).

First: on KDE Settings > Application Appearence > Fonts. Mark Anti-aliasing as "enabled", click on "Configure", UNcheck "Exclude range", check "Use subpixel", and select "Slight" for "Hinting".

Then do one of the following steps:

Workaround 1: go to KDE Settings, Font Management, and disable the "demi bold" and "light" variations from the font you're using.

Workaround 2: select a font with no "semi bold" and "light" variations, like Tahoma.

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Try this, it fixed my gtik application so hopefully will also fixe your gtk applications.

sudo apt-get install tk8.5
sudo update-alternatives --config wish
# a list will show up and you need to type in the number that corresponds to tk8.5 (in my case was 3) then hit enter
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Well, as a matter of fact - i tried that and firstly it appeared that i had no tk8.4 package at all - so no alternatives on update. But what ever - after installing, and rebooting it remained the same =(( – Danchik Oct 17 '12 at 3:51
You see, my problem appears ONLY in GTK based programs - in native KDE programs and in the overall Kubuntu 12.04.1 System i had no problems with fonts or any characters. – Danchik Oct 17 '12 at 3:54
The strangest thing that the pattern of the distortion changes each time i reboot, change the systems font defaults, hitting anti aliasing, etc. – Danchik Oct 17 '12 at 3:55
The same goes when i scale the page's fonts in Firefox by pressing "Ctrl" + "+"/"-". Looking forward for your comments! – Danchik Oct 17 '12 at 3:57
What i think is that i installed a clean installation of the / partition, but my /home directory was kept the same.Can it be that the source of the problem? – Danchik Oct 17 '12 at 4:45

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