Quality Park Tyvek White Open Side Expansion Envelopes 12" x 16" x 4" 50-CTN, strong material won't rip, tear or puncture. Expand to allow for easy insertion of bulky items like books, binders, catalogs, etc. Lightweight to help you save on postage, try these instead of a heavy box. Made from lightweight Tyvek material. Grip-Seal closure secures contents inside. Open End means the opening is on the smaller side of the envelope. Open Side means that the opening is on the longer side of the envelope for an even larger opening.
