Melamine boards usually consist of a particle board or MDF core.  The melamine, made of a resin, is laminated on to that core, thus creating a hardened surface.  This surface is very durable, so it will resist marks and scratches.

It works well for cabinets, closet storage, and shelving.  Toledo Plywood even sells pre-cut shelving in white with the front edge wrapped so the wood is not exposed.  This gives the self a clean look with none of the core exposed on the front.

Toledo Plywood carries sheets in white, black, almond, and wood-grain maple – in stock 4′ x 8′ at 1/4″, 1/2″, and 3/4″ thicknesses.