Mine is made from a 4'x6' foam core board from Home depot covered in a thin batting or you can use white felt. I hang it on the wall with the 3M hooks that stick to the wall, but can be removed without damage. It is great. Probably cost under $10.00 total. The nice thing is it will just hold your squares or you can pin them on it because it is about 1/2" thick.
Use mine all the time.