Abstract: The present invention pertains to a design for a carton blank for significantly enhancing the seal of a carton for packaging semi-liquids such as ice cream or the like without compromising the adaptability of the carton blank to mechanical folding devices. The carton blank includes front, bottom rear, and cover panels. A closure flap is hingedly connected to a top edge of the cover panel. The closure flap includes a tear strip for enabling a consumer to readily gain access to the contents of the carton. An end flap extends from each edge of the cover, rear, bottom and front panels. A cover or glue tab extends from each edge of the closure flap. A membrane extends from each of the front panel end flaps and the front panel for forming a substantially continuous lip about a potion of the outer periphery of the carton. The front panel membrane includes notches or recess at each end for receiving the corresponding ends of the front panel end flap membranes.