Quality Park 1-Side Print Interoffice Envelopes, String-Tie, Brown Kraft, 10 x 13, 100 per Carton, (63563) DURABLE: Made from heavyweight 28 lb. paper stock VISUAL CONFIRMATION: Holes punched on both sides of the envelope allow for visual confirmation of the contents without opening 31 ENTRIES: Printed on one side with space for 31 entries STRING-AND-BUTTON: Convenient when reusing the envelope, easy to open and close repeatedly GREAT VALUE: Conveniently packed in 100 count to reduce the frequency of repurchasing