Abstract: A carton of unitary structure which is adapted for heating food, especially frozen food, in a microwave oven. An openable removable top flap for the carton is formed by partially scoring the outer and inner surfaces of the top panel and providing slit lines or foraminating the front flap. The slit lines of foraminations in the front flap, preferably herringbone slit lines formed into the surface of the carton, extend from locations at a top flap crease in the top panel to positions adjacent a lifting tab portion provided at the free edge of the front flap. A pair of spaced apart first and second score lines are formed in the upper surface of the top panel along the crease line forming the folding edges of the side flaps and along the back flap, whereas a pair of third and fourth score lines in the lower surface are closely spaced apart from and in parallel with but wider spread apart than the first and second score lines.

Abstract: A carton of unitary structure which is adapted for heating food, especially frozen food, in a microwave oven. An openable top flap for the carton is formed by partially scoring the outer and inner surfaces of the top panel and providing slit lines or foraminating the front flap. The slit lines or foraminations in the front flap, preferably herringbone slit lines formed into the surface of the carton, extend from locations at a top flap crease in the top panel to positions adjacent a lifting tab portion provided at the free edge of the front flap. A pair of spaced apart first and second score lines are formed in the upper surface of the top panel extending along the adjoining edges of said upper panel and side panels of the carton, whereas a pair of third and fourth lower score lines in closely spaced apart from and in parallel with but wider spread apart than the first and second score lines.