These Alvin Archival Print Protectors are available in ten sizes, ranging from 11" x 14" to 32" x 43' and are made of a heavy weight, clear .010" polypropylene. Reinforced on all sides with black nylon binding for durability, one side has edging strips that are sewn. This side is open to allow for easy access. Alvin Archival Print Protectors have a neutral PH, are acid free and include an insert of black paper.. These protectors are guaranteed to be of archival quality, making them ideal for storing and presenting a wide range of print material, including family herilooms, photos, artwork, maps, old documents and more. Each pre-packaged box contains six protectors.