Columbian Brown Kraft Gummed 10 x 13 Inch Columbian Catalog Envelopes 100 Count (CO681) A durable ALL-PURPOSE mailing envelope. Ideal for mailing documents, catalogs, direct mail, promotional material, brochures and more. Heavy-duty 28lb opaque brown kraft material provides privacy of contents. Open end closure. Moisture activated gummed seal. 10" x 13" 100 envelopes