USPS First Class border and mirror image pre-printed message underscore your document's importance. Heavyweight paper stock resists ripping and bending. Wove finish provides a smear and smudge resistant printing surface. Gummed flap produces a secure seal. Envelope Size: 9 1/2 x 12 1/2; Envelope/Mailer Type: Catalog/Clasp; Closure: Gummed Flap.