Quality Park 9×12 Clasp Envelopes have a sturdy clasp and deeply gummed seal for keeping or mailing documents. Reduce waste and save with sturdy reusable envelopes perfect for inter office mail or storage. Our double prong clasp and reinforced eyelets are built for repeated use. Use the clasp envelope function for organizing and sorting projects. Or seal the heavyweight 28 lb. brown kraft envelopes and put them in the mail. These large envelopes can mail more cost effectively than bulky, stuffed #10 envelopes or more expensive oversized flats; the 9 x 12 mailer is the perfect compromise for cost-effective, professional-looking mailings with a little room to spare. Use 9×12 manila envelopes for mailing 8 x 10 photos, full letter-sized documents, contracts, catalogs, registration packets and other large flat correspondence without folds and creases. 100 per box.