I have read this column for years and lately I have been thinking about a design wall too. Now I think I came up with a good one. I think we should do them with the foam insulation board, but use them as doors on the bookcase or some other storage unit. We would have to add wood 1 x 3" or something to hold the hinges okay. Think about it, if
use have a good size room, use a far wall as storage and then use the doors as the design wall. That way you are doing double duty and not taking up two walls. We have to think double duty most of the time. If we do not hinge them to the bookcase(cupboard, etc), then we could slide them into a slot at the top and bottom to hold them so they do not tilt. I just have to go to the workshop and make this happen. Everyone, think about this in your space too.