golden state art, acid-free see-through sleeves storage clear bags for photo framing mats mattes (16 3/8x 20 1/8 inches for 16x20 photo mats, set of 50) golden state art the re-sealable adhesive strip is below the opening of the bag instead of on the flap. it can be folded over and sealed over the bag's opening. it can fit the below: 1. mat frame + backing+ print 2. mat frame + foam board + print 3. double mat frame + backing+ print 4. 8ply mat picture frame + backing+ print