Different Bristle behaviour with on/off GPU?

[IgorS]

It seems huge difference in opacity or color amount with on/off GPU with bristle feature. Here the example with default "Dirty impasto oil". I used pure black color, left strokes with GPU "on":

[support]

Yes, it's not a bug, that's why GPU off for bristle brushes by default - the way of it's realized via shaders (GPU) is a little different. It can be helpful only on big rounded brushes.

[IgorS]

Got it.