The problem is, I can't get sharp edges on brushes when I draw with my pen directly on my screen. I get these round edges and after a few hours fighting with the brush settings I finally realised that the sharp edges are possible but you need to add some black magic and sorcery. As you can see shown in the image below, no matter what I tried it stayed the same (left) When I press really hard and the slowly release the pressure I can get a sharp edge (right), but this method sucks.