|Originally posted by Knative|
I picked up the same / similar thing from Home Depot. It was more like a piece of paneling than cardboard in its construction. Heavier, too. Wood-ish on the back, shiny white plastic-ish on the front. I'm pretty sure it's what would be used to panel the walls in a bathroom. ~$10 for a sheet so I bought two while I was there with the truck. I found mine back with the other paneling & pegboard.
I'll check the extra piece when I get home and see what the sticker on the back says.