9 x 12 Open End Window Envelopes - 28lb. Bright White (1000 Qty.) | Perfect for Tax Season, Sending Catalogs, Pamphlets, Brochures and so much More! | 28lb Paper | 1590-1M USES: Catalogs, Annual Reports, Brochures, Magazines, Invitations and so much more! Applications: Business Mailings, Direct Mail, Corporate Mailings, Financial Mailings, Personal Mail. Size: 9 x 12 Open End Envelopes / 9 in. x 12 in. / 9" x 12" / 229mm x 305mm Printable on off-set printing presses and some home printers. Quantity: Pack of 1000 Color: 28lb. Bright White