I don't know what I was thinking, there is a 3d range near me that uses old/blem hot-tub covers as backstops! They will stop anything. The guy that runs it sells them for 30 bucks and they are like 6'X6'. I am going today to pick up 4 of them to cover the back wall of my garage. They will leave a little stuff on your arrow/ easily removed, but it is better than siding residue from the neighbors house or dog. If anyone of you do any shooting in the midwest, maybe I could hook you up.