IMPORTANT STEP: I should have mentioned that for brooches, I not only stick the pin on the back of the brooch using Zap-a-Gap or some other instant glue, but also, after the glue sets, I use Kato Polypaste to apply a thin piece of suitably-colored clay over both the base of the pin and a bit of the back of the brooch on both sides of the pin, pushing it a bit into the three holes (in the case of the kind of pin backs I get from FireMountain Gems) on the flat part of the metal pin, and then bake once more. After which I apply the Varathane. Having spent enough time trying to get the photo onto the clay (often some pieces have to be discarded), I never want to lose a brooch just because the pin on the back has become detached. The Polypaste is necessary, because without special help, it is impossible to bake a piece of raw clay onto a piece of clay that has already been baked, and I believe most glues cannot be trusted to hold well under baking, hence my addition of a new piece of clay to be baked on. Kato Liquid Polymer Clay will work for this purpose with some things that do not get any stress, but I would not trust anything but the much thicker Polypaste to hold the pin on a brooch. I got this idea from someone else's post somewhere--most likely not here--and I wish I could remember who, so that I could give them credit.