Abstract: A container is provided in the form of a cup-like container body with a round mouth closed by a lid which becomes removably replaceable upon tearing away of a circumferentially extending tear strip which initially surrounds the mouth rim of the container body as a radially outer, integral part of the lid flange. As the lid is differential pressure-thermoformed, its radially outer region is formed into a generally inverted U-shaped structure which near the juncture of the base and radially outer leg of the inverted U, is provided, within the channel, with an inverted V-shaped notch of substantially diminished wall thickness to provide a line of weakness which preferably extends nearly fully around the circumference of the lid, but for at an angularly short tear-starting site.