I have two insulation boards 2" thick. I covered them with felt, using clear 2" packing tape for the edges, as if I were doing gift wrapping. Tape is on the back, but also along the edge that sits on the floor so they slide easily and stay clean. I still use pins to make sure pieces will stay in place. Because they're 2" thick, pins stay in well. Felt is white and was on sale at JoAnn's. I love my design boards and keep things I've done or that inspire me on it, besides using it for design.