forgot this too, I havent tried it but i think it would work ... export the head object into uvmapper, save it again, but choose to "flip normals". Then select the face material and rename the group face, then import it back into poser ... then in the heiarchy editor, select the face group of your imported object and hide it, and move the head half into position so it covers the back of his head .... this way you should be able to paint on the inside of his head, and the front of his head wont be in the way.