See below for details and proof. When the resolution is set to 1440x900 (my native) or lower, the textures are blurry regardless of graphic settings. Please remedy this bug. Thanks!
Here's a screenshot showing what I mean.
https://drive.google.com/file/d/1NAXW2pUydJh2ZACA3dtHxMruo_oHYQ-5/view?usp=sharing
Update: I figured something out, but I don't know what to do with it. I played around with the resolution and discovered that if I adjust the resolution to slightly off my native 1440x900 it causes all the models to be blurry because they are slightly squished. When I went back to my native resolution and looked again at the inventory screen, I realized that the character models displayed there are slightly squished causing the blurriness. Why they are squished there and nowhere else I can't explain nor do I know how to fix such an issue. Let me know if you can think of anything. I am using an Nvidia card if that helps.
I just responded on GOG to your post (you used the same nick, so I assume it is you!), but it looks like resolutions of 1440x900 or less seem to have the problem with creating blurring avatars.
For references, an image showing the blurryness at 1440x900 (windowed mode since my monitors native resolution is 1920x1200):
https://i.imgur.com/lI5d1tc.png
And the issue disappears (for me at least, unsure if OP can test higher resolutions) once the resolution is increased 1600x900:
https://i.imgur.com/0ZkXaal.png
I just came here to update this thread with your response! You are amazing! It's a confirmed bug so hopefully it will be addressed in a patch soon.