Originally Posted by Butsky
Upper hinged bunk cushion is ONLY one with vinyl is is not reversible, either...
Don't worry about it, just do what works best for your needs.
I like to place a piece of the EVA foam yoga mat on the boards under my cushions, this keep them from sliding around and helps reduce the wear on the fabric. It also adds a little extra cushion and even some extra insulation. Vinyl is too slippery, especially for an upper bunk cushion backing.