This includes wood, cardboard, glass, metal, and many plastics. If you're not sure whether a plastic item can be fired without melting, try running it through the dishwasher to test its melting temperature. To veneer a piece, apply a thin layer of clay to it. To keep the clay from peeling away from an object while you're working with it, you can paint a thin layer of Liquid Sculpey on the object and fire it for a few minutes to set it, then layer your clay on top. Another technique to make clay stick is to layer the piece with glue and let it dry to tackiness before putting the clay on.
Any object expands when heated and contracts when cooled.
When you're baking clay on some object, it's a good idea to put it into a cold oven and then turn on the heat, and leave it in the oven after firing until it's cool. Changing the temperature slowly instead of fast lets the clay adjust as the size of the veneered object changes, and this reduces the possiblity of cracking. To create clay shapes, first roll out a flat sheet of clay. If the clay sticks to the cutters, use a little mold release on the clay before cutting, or chill the clay a little before you cut it. The shapes can be used as-is for pendants or ornaments, or layered in various colors to create interesting effects.