My son made me two out of 4'x8' sound boards. You can get them at Home Depot. They are soft enough to stick a pin into. But because they are soft, they also bend. So he took 1/2" x 2" boards and put them on the back, first all around the edges, then in an "X" across. They now just lean up against the wall and I can move them if necessary. Then I covered them with 1 or 2 layers of cheap batting from WalMart stapled to the back. They are wonderful.