notes for Painting in zbrush:
base color
left panel -> Materials -> skin shade 4 top -> Mrgb disable Zadd and Zsub (so we're only painting color) top menubar color -> fill object
painting on a texture with spotlight
texture icon (left) -> import texture menu (top) -> select texture -> icon add to spotlight (right under the texture previews, last icons!) click inside the circle and drag to move turn opacity down to see model shift - Z to enable/disable sportlight z to get circle back select standard brush enable Mrgb, disable Zadd