Bug 508056

Summary: Adwaita Sans bold font looks blurry across KDE applications
Product: [I don't know] kde Reporter: Akseli Lahtinen <akselmo>
Component: generalAssignee: Unassigned bugs <unassigned-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: kdedev, nate
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Adwaita Sans font
Inter font
Empty font weight

Description Akseli Lahtinen 2025-08-09 16:34:07 UTC 
Created attachment 183909 [details]
Adwaita Sans font

SUMMARY

I'm unsure if this is Qt bug, Freetype bug or KDE bug... 

Anyway, when using Adwaita Sans font, it looks oddly blurry with bold weight.
However, regular Inter font looks fine.

STEPS TO REPRODUCE
1. Install Adwaita Sans font
2. Set it as your font

OBSERVED RESULT
Anything bold looks weird

EXPECTED RESULT
Anything bold would look same as the Inter

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.80
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.1
Kernel Version: 6.15.9-201.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 3600 6-Core Processor
Memory: 16 GiB of RAM (15.5 GiB usable)
Graphics Processor: AMD Radeon RX 6600


ADDITIONAL INFORMATION

There was already prior bugreport in GNOME bug tracker here: https://gitlab.gnome.org/GNOME/adwaita-fonts/-/issues/2
Comment 1 Akseli Lahtinen 2025-08-09 16:34:25 UTC 
Created attachment 183910 [details]
Inter font
Comment 2 Akseli Lahtinen 2025-08-09 16:35:46 UTC 
I tried to see if setting following to /etc/environment would have any effect:

```
FREETYPE_PROPERTIES="cff:no-stem-darkening=0 autofitter:no-stem-darkening=0"
```

or 

```
FREETYPE_PROPERTIES="cff:no-stem-darkening=1 autofitter:no-stem-darkening=1"
```

However with stem-darkening off it got significantly worse (a lot more jagged), so it's not that at least.
Comment 3 Akseli Lahtinen 2025-08-09 18:00:43 UTC 
Created attachment 183912 [details]
Empty font weight

I made another report for this in here: https://gitlab.gnome.org/GNOME/adwaita-fonts/-/issues/21

It might be a bug in the inter font itself. Unsure. But we should definitely ignore the empty font weight like shown in the image.
Comment 4 Nate Graham 2025-09-24 20:42:55 UTC 
It's definitely not a KDE bug, as we don't do anything with font rendering. It's a Qt bug, a FreeType bug, a FontConfig bug or distro-specific misconfiguration, or a bug in the font itself interacting with any of the above.