Paper drink cup lid with stacking and sealing features

A lid formed from a single piece of paper material and configured for use with a container having a container sidewall and an annular rim extending around an open upper end of the container, the annular rim including a curved outer surface, the lid comprising:

• a planar center portion having a diameter less than the diameter of the annular rim;
• a nesting lug joined to the center portion and extending above the center portion, the nesting lug defining a receiving cavity sized to closely correspond to curved outer surface of the annular rim;
• a support shoulder extending radially outward from the nesting lug;
• a skirt extending from the support shoulder, the skirt including an outer wall and an inner wall joined to each other;
• and
• a locking skirt tab extending from an end of the inner wall and into the receiving cavity of the nesting lug from the inner wall,
• wherein when the lid is installed on the container, the receiving cavity of the nesting lug is in contact with the outer surface of the annular rim to create a seal therebetween and the locking skirt tab engages the annular rim below an equator of the annular rim to hold the annular rim in the receiving cavity.