Abstract: The envelope is especially designed to bulky contents such as bank statements with cancelled checks and the like. The back panel of the envelope is provided with a rupturable cut score line which is parallel to the bottom edge of the envelope and which is overlain by the closure flap of the envelope when the latter is closed. An initiating tab projects below the lower edge of the closure flap. The lower edge of the closure flap is parallel to the bottom edge of the envelope, and the closure flap is secured to the back panel of the envelope by a latex adhesive which is adherent without being moistened. Adhesive spots are provided on the inner surface of the envelope to releasably secure the contents in place in the envelope.