10" x 13" x 1-1/2" expansion envelopes expand 1-1/2" to provide lightweight, cost-efficient shipping for bulky items. 14 lb. DuPont Tyvek material resists punctures, tears and moisture. They are half the weight of heavy-duty paper envelopes to help save on postage with each mailing. Tough, expandable design resists overstuffing, bad weather and rough handling to deliver your contents intact. Redi-Strip closure is easy to use. Just peel and press for an instant seal. Redi-Strip envelopes are the perfect answer for concerns about surface germs in the workplace. Save time and cut the waste with every mailing. Peelable strip protects the adhesive from dust to last longer in storage. Large envelopes make a versatile mailer for all kinds of thick enclosures from paper to textiles. They open wide to accommodate binders, books, manuscripts, transcripts and more.