Originally Posted by QuiltE

Polar fleece works well as a design wall.
Simplicity, can be it pinned or taped to the wall.

Mine is polar fleece, stapled to homosote, and then that is screwed to the wall.
Total size is 11'x8'

Also did the same with fleece over corrugated plastic.
I have multiple sizes from 15" square to 24" and onwards up to the full 4'x8' corrugated.
These slide nicely behind a piece of furniture when not being used. Or into the back of a closet.

Fleece holds the blocks well with out pinning. I've even had full flimsy's on my large design wall with no pins, But, I still like the ability to pin something, to be sure it does not move, or because I am at the edge and the block goes beyond. Then I can!

Really depends on what size you want and what restrictions you have in your sewing room.
You can never have enough design walls!