Vtmtnman, If you like cheap material to start out with you can knap bottle bottoms beer, wine, yeagermeister green bottle bottom, plate glass if you can find thicker stuff,tv screens just make sure an wash off the dust thats inside :( Here's a little tip on getting bottle bottoms off real easy. Make sure an wear glove for protection, drop a 20D nail in bottle an place hand over top an shake it up an down until bottom pops off nice an clean. Works just like you had it cut off. Have fun an becarful. Bob