I had a slight problem with paint chipping off the back! If anyone has any suggestions on how to avoid this happening the next time around I would really appreciate it!
You don't say what type of paint (and finish) you used, but I assume it was acrylic since that works best for "painting over" baked polymer clay.
Next time, if you didn't already, you might try cleaning the areas you'll be painting with alcohol first to make sure there is no hand oil, or anything else that's acting as a resist for the paint.
You might also want to wait awhile before subjecting acrylic paint or clear acrylic finish to stress and abraision because although they "dry" fairly quickly, they don't completely "cure" and achieve their greatest strength for about a week.
Ways to avoid the problem in the first place though would be to:
...use colored polymer clay instead (or color SuperSculpey yourself --if you do, be sure to add at least a bit of white clay or white oil paint as well as any color you want because whites are very opaque and will keep the SS from being translucent)
... if you marble two or more colored clays together, you could end up with a similar effect (then add a gloss sealer if you want, or sand and electric buff
the piece to a glossy shine)
..."highlight" or "antique" one of the clay colors with the other color (of paint, ink, metallic powder, etc.), so you can add add that second color separately and just where you want it
......for the pieces you show, an example might be making the faces in-off white clay, then highlighting and/or antiquing with a green, rose or yellow acrylic paint (tube-type best) or artists' oil paint --acrylic will be more opaque than oil, if that matters-- or with a metallic powder (like gold), or with a non-metallic pigment like ground-up artists pastels or ordinary chalk, or various other things
.....or in reverse, you could make the faces with green, rose or yellow clay, then dab or rub on an off white paint/powder/etc.... sometimes a sealer would be needed, sometimes not
(...you could also mix the powders into a clear acrylic finish and use them like a paint, for dabbing, rubbing, etc.)
(if you're interested in more info about highlighting and antiquing dimensional surfaces, look on this page:http://www.glassattic.com/polymer/molds.htm
...click on Antiquing, Highlighting and Staining
at the bottom of the list at the top of that page)