Your growing collection deserves the best archival storage for now and in the future. The UniKeep Postcard Collector Case with 20 pages will store and protect your cards from the damaging effects of the elements for years to come. The Unikeep case is made from acid-free polypropylene and will not harm your collection. The cases stack easily on a shelf or a table and do not take up much space. The archival quality pages offer a protective buffer against damage so you can admire and display your collection with confidence. Postcards up to 4" x 6" will fit in the pages. The pages hold 6 postcards per page when stored back-to-back.