Alternatively, the first layer of material may comprise a film or open or closed cell foam material Suitable film or foam materials are cast or extruded films or foams formed from polyolefins such as polyethylene and propylene, polyesters, nylons, ethylene vinyl acetate, ethylene methacrylate, copolymers of the above materials, block copolymers such as A-B-A block copolymers of styrene and butadie