Seem the same on my MacBook Pro. Over the paint team cause they might have an idea.

There are two pathways for drawing background images: one for single-copy cases like the example logically is, and one for repeated cases. I believe that the improvements to sub-pixel background positioning have resulted in the path changing for the particular case. It's probably changed to use the non-repeating path since no-repeat causes the blurriness.

On my MacBook the difference is not visually noticeable although there are anti-aliasing differences if you magnify the screen.

I'll try to reproduce somewhere and bisect to confirm my understanding.

FWIW, for me the blurriness goes the other way.

Thanks for the quick triage & analysis.

The way this materializes in my actual application makes it appear worse than the demo -- our font sizes must be slightly larger such that the difference causes the background to also be a couple pixels higher and to the left in addition to being blurry, which results in it being off-center (screenshot attached).

Deleted: blurry checkboxes.png 7.3 KB

	blurry checkboxes.png 7.3 KB View Download

Thanks for the additional info that should help me reproduce. Sensitivity to size definitely suggests the issue is the different paths. The shift in the image is concerning, however. I would not expect that.