I already tried that several times, Anton, really, but my knowledge of layering shaders with math functions in Poser's MAT Room is very basic and 'till now I couldn't come up with a satisfying solution. And the maps always need to be very high-res, but most users don't have those resources to handle several high-resolution maps at once. So I had to make compromises somehow.

If it would be that easy, everyone could do that with my "David Hairy" and "Freaky Hairy" things, those are "white hair on black" maps.