Abstract: A method and means for manufacturing a plastic lid with a frangible portion to facilitate the formation of an aperture is described. In one embodiment a platen having ruled steel cutting blades mounted thereon is pressed against a plastic lid backed up by a hardened steel anvil with sufficient force to merely score the plastic lid in accordance with the pattern of the cutting blades without actually breaking through the plastic lid. The scored area which forms said frangible portion of the lid may then be easily punctured to form a straw-slot or vent opening. In another embodiment the cutting tool used comprises two cutting blades disposed on intersecting paths, each blade having a portion removed adjacent the point of intersection of said paths. In this embodiment the cutting blades are permitted to cut completely through the lid leaving a diamond-shaped weakened area in the region corresponding to the intersection of said cutting blades.