Do you mean foam insulation sheets from Home Depot? Or do you mean Foam Core like from Office Max or similar store?
I used the foam insulation sheets for my design wall. It is actually 2 sheets, each 4' x 8', duct taped together. I use just the folded outer side usually, but can fold it all out for larger projects. I take pictures of what I want then fold the design wall back up. I did have to trim the height just a bit so it wouldn't hit the ceiling fan in the studio as I folded it up and then out again. I made a vinyl footing [a cover for the bottom of the design wall] so it wouldn't get dusty just being on the floor. I have colorful ribbon attached to eye hooks at the upper level to keep the design wall upright.
One friend didn't have the room for such a big wall so she used brackets to hold her smaller design wall onto her studio wall.