Well I finally got to try copper clay. Took 3 firings in my little Paragon Caldera Kiln to produce reasonable results. Still some bugs to work out (mainly in areas where cracking occurred), but for the most part its pretty easy to handle: works much like porcelain only spongier and stickier. I was pleasantly surprised to learn that it is MUCH easier to work in the leather-hard stage than traditional clay. You can sand it, drill it, etc. - it's very sturdy and tough, unlike traditional clay which is much more likely to crumble or break.