About this item Columbian 9" x 12" Catalog Envelopes fit large letters, catalogs or photos flat, without folds or creases; heavy-duty 28 lb kraft envelopes provide privacy durability with easy self seal closure Release Seal self seal envelopes make mail day easy; just pull the paper strip and press? no moisture required; strips protect your adhesive from dust so envelopes last longer in storage These sturdy large envelopes are manufactured from heavyweight 28 lb. brown kraft paper for durability in mailing or storage; top-loading envelopes make it easy to drop in flyers or other enclosures 9 x 12 mailing envelopes are perfect for shipping letter size contracts, catalogs, registration packets, 8 x 10 photos and other paper enclosures; ideal for flat rate mailings 30 Packs are the perfect amount of peel and seal envelopes so you have just enough at home, the office or school; perfect for mailing, sorting and storing paperwork