It depends on how much you wet it. If you use minimal water (say, a wet brush) it'll be quite thick and richly coloured. However, if you wet the makeup itself, you can get a watercolour effect.
Pancake makeup is quite fun because you can do so much with it!
I spent two week scovered in kelly green pancake makeup (face, arms, and neck) to play a witch.....never again! I had green eyebrows for a month!
