The Sizzix dies by Tim Holtz are my favorite cutting dies for my Big Shot cutting-and-embossing machine.  They're thick, sturdy, and sharp enough to cut through thin metal and wood in addition to the usual paper and cardstock.  With this "Hardware Findings" die, I've used both metal and heavy cardstock.  With the metal cut-outs, I used different rusting techniques which looked great.  I used a random "bumpy" patterned embossing folder on the cardstock cut-outs and then used some painting techniques to age the "hardware."  A bit of crackle-finish jazzed them up even more.