Abstract: A mailing envelope (10) has a stick down closure flap (11) extending from a fold line (12) along the top edge of a front panel (20). The closure flap (11) includes a graspable tear-out tab (19) to which is adhered a flexible line member (18) which extends across and is adhered to the envelope internally thereof. The envelope (10) may be opened by grasping the tab (19), with the line member adhered thereto, and pulling the tab (19) and the line member (18) away from the envelope to cause the line member (18) to tear through the envelope along the length of the line member. Preferably the line member (18) is secured to the flap (11) along it fold line (12).