15" x 20" Jumbo Catalog Envelopes feature ungummed flaps and are made of heavyweight, 28 lb. brown Kraft stock for home or office storing, organizing and transporting. 28 lb. Kraft stock withstands extensive handling and reuse. Envelopes are perfect for storing large items such as blueprints, artwork or photography without folding. Ungummed flap allows repeated use.15" x 20" Jumbo Catalog Envelopes feature ungummed flaps and are made of heavyweight, 28 lb. brown Kraft stock for home or office storing, organizing and transporting. 28 lb. Kraft stock withstands extensive handling and reuse. Envelopes are perfect for storing large items such as blueprints, artwork or photography without folding. Ungummed flap allows repeated use.