Abstract: An envelope which is closed and secured without adhesive for repeated use. A tuck, flap extension of the closure flap is infolded and tucked back in between the back panel and a lock flap partially overlying the back panel. The back panel and the lock flap, folded back upon it, are secured to the front panel by overlying end tabs.

Abstract: An easily opened, non-adhesively closed envelope includes a closure flap extending from the top front edge thereof with a tuck flap extending from the outer edge of such closure flap. A locking flap is disposed in a downfolded, overlying manner from the top back edge of the envelope and, being adhesively attached to only one side edge of the envelope, provides an open-ended pocket into which the tuck flap is inserted. The tuck flap is held between the back of the envelope and the inner side of the locking flap in sandwich fashion so as to maintain the envelope in a closed disposition. The tuck flap is offset from the centerline of the envelope towards the side edge thereof adjacent to which the locking flap provides the open pocket for receiving the tuck flap. Increased facility of engaging and disengaging the tuck flap from the open pocket defined by the locking flap is thereby provided.