9-1/2" x 12-1/2" ( 9.5" x 12.5" ), Open End Catalog Envelope, No Window, Ultra-White, Bright White Sulphite Paper (96% Brightness), SFI Certified, Vellum Finish, Center Seam, Flap Down, Kwik-Tak Seal, 500 Qty / Box, 500 Qty / Ctn, 22 lbs. per Box