Just thought I'd mention for anyone looking for foam plates, you can order a set from these guys:
https://www.facebook.com/JTacCustom. They're cut to the proper size/shape of real plates, and they're supposed to be good. So if you want something a little nicer than homemade stuff, but not "$200 training plate" level, maybe check them out?
I first heard about them from this review on The Reptile House if you want more info:
http://thereptilehouseblog.com/2014/03/10/j-tac-custom/