I stopped at a pet shop last year that sold lizards, etc. and asked if they had cork for sale (it's usually cheaper there than at a garden center). The guy said "oh, we have one piece............someone brought a lizard in and brought a piece of cork. We don't want it.........you can HAVE it!!!" What a deal. Haven't used it yet...........but I will find a need!
It's maybe 8x12 or so.