I got a large piece like that from a sign store. If you search sign stores in your area you can probably find one. My piece ended up costing $10 - $20 (I forget...). It ended up making a great 3x5 C&C cage for my 3 girls!
Man the coro i used is so tough you couldn't roll it like that. One side is very tough to cut and the other very easy. It will last forever and i don't think i'll need to replace it.