Buy these JAM Paper 9.75" x 13" Black Plastic Button String Open End Envelopes, 108ct. at Michaels.com. Whether your documents are sitting inside of your desk drawers, making an appearance in the class room or being transported from place to place, these envelopes keep them orderly and safe from damage. Each one is made of pliable and sturdy plastic and has a secure two button string tie closure.