Clasp Envelope, 28 lb Bond Weight Kraft, #97, Square Flap, Clasp/Gummed Closure, 10 x 13, Brown Kraft, 100/BoxReusable, so you can substantially reduce purchasing.Heavyweight brown kraft stock protects contents during mailing, storage and handling.Unmarked and smooth, the windowless surface has plenty of space available for labeling, printing and writing.