Since 2.10.18 (and I think this problem may have started in 2.10.16) the brush engine is constantly creating hot pixels in areas with transparency.
The engine now does mip-mapping I think. This may be the cause. I even tried making brush sizes in powers of 2 (like 16,32,64,128 ...) hoping it might fix the issue. It doesn't.
I may need some help joining the bug reporting site instead of just posting here. Having full color bit map brushes is one of the advantages that puts Gimp ahead of Photoshop, and it now appears broken.
Tested same brush in 2.8
The engine now does mip-mapping I think. This may be the cause. I even tried making brush sizes in powers of 2 (like 16,32,64,128 ...) hoping it might fix the issue. It doesn't.
I may need some help joining the bug reporting site instead of just posting here. Having full color bit map brushes is one of the advantages that puts Gimp ahead of Photoshop, and it now appears broken.
Tested same brush in 2.8