Oh, my. I had no idea these things existed! They look wonderful, but I have so many fabrics..... Aside from $2 a board (including bolt buddy and shipping), the bookcases I would have to buy, I shudder to think about how much time it would take me to refold it all. Still, it would look fabulous!
The cardboard sheets would be wrapped in sheeting to protect the fabric from direct contact with wood acid. The sheeting wouldn't have to be sewn; just cut, folded top and bottom, then wrapped and fastened together with a couple of straight pins. More work, though. (Can you tell I'm lazy? :D )