Alvin blueprint bags make packaging and shipping blueprints hassle-free. White exterior /gray interior opaque bags are made of heavyweight .0035mil. co-extruded plastic material. These weather and tear resistant envelopes are extremely durable and easy to use. Bags are designed with a permanent self-sealing 3” lip. Bags accept self-adhesive labels and permanent markers with ease. 9.5” x 33” + 3” lip. 100/box.