Krystal Seal is an acid-free archival environment for the storage and protection of artwork, photographs and documents. Each bag has a resealable flap so that it can be used time and time again. Perfect for displaying or storing all traditional and modern sized items, including those used for printmaking, photography, watercolors and inkjet prints. The 2-1/2" x 3-1/2" sized bags are especially designed to hold artist trading cards.