Itoya Polyzip Art and Photo Envelopes are a great way to store your art and photography. Made of clear, durable polypropylene, they are archival safe for long term storage. Featuring an easy to use zip closure that seals out the elements to resist dust and moisture and an expanding 1 1/4" gusset for extra storage. This PolyZip Envelope comfortably holds items up to 20x26 inches.