Thanks to a post on Tumblr I bought a couple of six packs of these upcycled vinyl picks from ThinkGeek. Mabe by Revived Vinyl they're just shy of 1.0mm thick with rough edges. I may try to smooth the edge on one of them with a polishing block but for now I'm liking the scratchy feel and tone these picks provide. I've tried to make picks out of old records before but only ended up breaking a pair of first generation Pick Punches. At only a $1 per pick it's much easier to just buy them!