Bug 504541

Summary: Bad bold font rendering
Product: [I don't know] kde Reporter: Lalit Shankar Chowdhury <lalitshankarch>
Component: generalAssignee: Unassigned bugs mailing-list <unassigned-bugs>
Status: RESOLVED UPSTREAM    
Severity: normal CC: deniso99, kde, lalitshankarch, nate
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Observed

Description Lalit Shankar Chowdhury 2025-05-19 18:05:01 UTC
Created attachment 181532 [details]
Observed

SUMMARY

Bad font rendering for bold fonts.

STEPS TO REPRODUCE
1. Change UI font to Adwaita Sans/Inter
2. Hover over the clock widget

OBSERVED RESULT

The correct bold version of the font is not picked. Instead, it's artifically bolded which makes the bold text look bad. (Attached screenshot)

EXPECTED RESULT

Bold font is rendered properly in About page of settings.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 6.14.6-2-cachyos
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.0
Comment 1 Nate Graham 2025-05-19 18:49:25 UTC
We're just using the standard "make it bold" code, which means this is an issue with either Qt itself, or the fontconfig  setup on the machine.

I have a vague memory of a Qt bug report about this a year or so ago, but I can't find it now.

In the meantime, talking with your distro folks about the fontconfig they ship may be useful.
Comment 2 Nate Graham 2025-05-19 19:22:23 UTC
I've found various Qt issues about bad bold font rendering, especially with non-default fonts. See:
- https://bugreports.qt.io/browse/QTBUG-131574
- https://bugreports.qt.io/browse/QTBUG-46042
- https://bugreports.qt.io/browse/QTBUG-63792

If it's not one of these, it's probably something similar.
Comment 3 John Kizer 2025-05-22 05:51:56 UTC
*** Bug 483334 has been marked as a duplicate of this bug. ***