Business Source 28 lb. White Catalog Envelopes - Catalog - #10 1/2 - 9" Width x 12" Length - 28 lb - Gummed - Wove - 250 / Box - White - Heavy-duty, all-purpose mailing envelope is ideal for mailing documents, catalogs, direct mail, promotional material, brochures and more. 28 lb. opaque white wove construction delivers privacy of contents. Open-ended style allows easy insertion and removal of items. Moisture-activated gummed flap ensures a secure seal.