Design wall
I also use insulation board a and just covered with warm and natural batting and gorilla tape to the back it is sturdy enough to lean against the wall and blocks stick to it really well. If lm auditioning a border around a big chunk of quilt I sometimes have to put a couple of pins into the board to hold up large segmented pieces. I have a second one that I can put side by side and get a full. 8 feetof design wall. Blocks will also stick over one board and on to the other. They are light enough to move easily