I used black fleece for my design wall. It's stretched on four foot widths of tentest. Total wall size 10'x7'-1/2".
It's been up for over two years now ... and I can't imagine working with out it. I NEVER need pins ..... and have had full sized quilts totally sewn together displayed on it for weeks at a time. (pressed and waiting to go for quilting)
I also made some smaller portable design walls with the offcuts. Works great at the sewing machine and iron. Or for just putting a few pieces together.