[rp12367]

I buy Elmer's foam board at Walmart it cost about $6.50 for a 4 pack. You can cut it with a utility knife to size, and you can get quite a few pieces out of a sheet. It is very light weight and very rigid. Depending on the value, I put one or two pieces taped to a bagged slab and then mail in a bubble envelope. The stuff is tuff to bend, so tuff I also use it for comics as well. Luckily never had a problem and buyers love it.