9" x 12" catalog envelopes are made from 24 lb. brown Kraft stock with 100 percent recycled content. Envelopes feature an easy-to-use, Redi-Strip closure. Just peel and press for an instant seal - no moisture required. Redi-Strip envelopes are the perfect answer for concerns about surface germs in the workplace. Stay safe and save time with every mailing. Peelable strip protects the adhesive from dust to last longer in storage. Brown Kraft paper has longer, stronger fibers than woven paper for better durability. Center seal adds strength to handle heavy contents. They are ideal for hand-addressed or labeled letters but are not recommended for printing due to the natural color and texture of the paper. Opaque construction protects private contents and lends a sophisticated, rustic tough to your communications. Large envelopes are ideal for photos, art prints, certificates, registration materials or any letter or oversized papers you prefer not to fold.