I've used one layer of batting. Perhaps I'll use it in a quilt and go buy a flannel sheet.

I just used a white flannel sheet from Walmart.

I am setting up a new quilting studio and want to make a design wall. My wall area will fit an 8' x 8' design wall. I have read about insulation board. Is it better to cover it with batting and/or flannel? If batting, how many layers are recommended? Thank you for any advice.