Polyropylene

A plastic material highly suitable for the acid-free archival storage of works on paper and other small two-dimensional object.Also see bin, collect, deltiologist, ephemera, exonumia, frame, memorabilia, philately, polyester resins, polyethylene, polymer, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride (PVC), portfolio, scripophily, solander box, and trademark (?).