Now you can protect your photos, ephemera, maps, or documents safely and easily between clear sheets of archival quality polyester using no adhesives. These Self-Sealing L-Velopes are made of Mylar-D to support their contents and protect them from stress, dirt, fingerprints, and atmospheric pollutants. Great for temporary displays or items that need to be handled frequently. Easy to use. Sold in packages of 5 L-Velopes. 9 in. x 12 in. and 11 in. x 14 in. L-Velopes are 3 mm thick. 18 in. x 24 in. are 4 mm thick, Acid-free.