"Quality Park 9 x 12 inch booklet-style catalog envelopes open on the long side for easy stuffing and inserting. Booklet envelopes are a simple solution for document storage and mailings. Heavyweight 28 lb white wove envelopes have gummed closures with a thick strip of adhesive activated by moisture. For mailing, use an envelope moistener for a strong, sanitary seal. For sorting, keep brochures, documents and other papers you're sorting or filing pristine in these crisp, easy to file envelopes. Heavyweight paper helps keep private contents concealed in a crisp, white wove stock. Accommodates over-sized documents so you can send catalogs, letter size papers and large photos flat without unsightly folds and creases. Stock up for home, office and school with convenient boxes of 250. "