Columbian CO729 6x9-Inch Catalog Self-Seal Brown Kraft Envelopes, 100 Count A durable ALL-PURPOSE mailing envelope. Ideal for mailing documents, catalogs, direct mail, promotional material, brochures and more. Convenient and secure self-sealing Self-Seal closure. Simply fold flap down and press for a quick seal. Heavy-duty 28lb opaque brown kraft material provides privacy of contents. Open end closure. 6" x 9" 100 envelopes Catalog envelope with a 28-lb. paper stock. Use for mailing documents, catalogs, direct mail, promotional materials, and brochures. Heavyweight 28-lb. stock. Durable.