An envelope has a flap portion (2), intended to be folded and glued to a body portion (1) of the envelope for its closure. It includes an opening device formed by a wire-like member (3) fastened onto the envelope along the fold separating body portion (1) from the flap portion (2). This member (3) extends beyond the envelope at least one of its sides for grasping manually by a user to open the envelope. The member (3) is glued to the fold and comprises natural or synthetic textile fibres or a plastics tape. <IMAGE>
