If I were to put a face-up/airbrush some color onto a sculpt after it's been primed will that affect it's ability to be cast later? Could I just prime over the head again. Does paint (if sealed) have any effect on the silicone moulding process or would it just come off on a junk cast? I've just not seen anything about this before (maybe because I'm the only one ridiculous enough to wanna do a whole face-up on a pre-cast version) but I wanted to ask some opinions before I go ahead and do it.
While I haven't worked with silicone, I know some people spray MSC over the primer to avoid a too shiny texture, so it shouldn't have any negative effects by itself. However a proper face up takes more layers, and layered sealant can crack or get a different texture, so I wouldn't risk it.
I've never done a full face on a pre-cast, but I've done basic blushing and line work. I was able to primer over with no complications.