I went through a phase (that I may or may not have completely finished going through, but we'll just see about that...) where I made theatre masks. I got one job out of it, and was offered another by the same person (a friend of mine who is a drama teacher at primary/elementary schools).
So there I am, trying to make some masks on a male head and I realise that it's too big for a kid's face. So I decide to use a female one instead.
I figured that if I wanted the eye-holes on the masks to be symmetrical and everything, that I needed to spray it black. With black spray paint.
That's when the face melted.
Oh yeah, I should probably mention that the heads I'm talking about are made of polystyrene. Not flesh.