Alvin blueprint shipping bags make packaging and shipping blueprints hassle-free. White exterior with 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. Designed with a permanent self-sealing lip, they accept self-adhesive labels and permanent markers with ease. 13" x 46" + 3" lip. BOX of 100. Alvin blueprint mailing bags are made in the USA.