Photoshop has trouple with hand painting in general, and narrow lines especially, try sizing up your image (at least double, more is better, then sizing it back down when finished. Painter, combined with a tablet does a lot better, though. The scratchboard tool seems to work especailly well. Sometimes I'm suprized how limited Photoshop is, for a $600 program. Try doing any work over a 50% gray background, for example - Photoshop used 50% gray for most of the tools, you can't see what you are doing!