Remember the Seinfeld episode where George was apologizing for shrinkage? Well this post is about shrinkage but not that shrinkage. It's about the shrink factor associated with metal clay.
Pmc standard shrinks 30%, Pmc+ and Pmc3 shrink about 12-15%. Most of the time I don't really pay much attention to the shrinkage factor since it doesn't really matter, unless I'm making rings or something that has to fit together. (Then it becomes a math adventure which is okay when all works out. But it can drive me to tears when it doesn't. I use to get stressed and cry when I couldn't figure out those darn word problems in high school.)
Shrinkage came in handy for my latest project. The customer had seen a dragonfly on a dicrohic piece and wanted a dragonfly on her earrings and matching necklace. The dragonfly was rather large, much too large for what she wanted. The solution was to use my dragonfly mold with Pmc standard which would shrink considerably, fire it and make another mold of the smaller dragonfly. That piece would work on the necklace but not the earrings. So....... it was use the new mold with Pmc standard and fire it again, thus reducing it's size again and making yet another mold. (The white dragonflies are fired, just not brushed yet.) The third mold did the trick. It was just the right size.
Now I have to figure out what to do with all the extra dragonflies!