Die-cut lid and associated container and method

A die-cut lid for closing a container, the lid comprising:

• a planar element formed from a flexible composite sheet material and having at least an outer face and an inner face, the outer face and the inner face being formed of different materials;
• a functional area bearing human-readable and/or machine-readable data on the outer face;
• one or more rigidifying indentations to promote flatness of the functional area in a resting state of the lid;
• wherein the one or more rigidifying indentations are one or more encircling indentations that border the functional area;
• wherein the one or more rigidifying indentations are formed from the flexible composite sheet material and are arched to protrude convexly from the outer face of the lid, such that a corresponding recess is formed in the inner face of the of the lid;
• wherein the composite sheet material has embossing over at least a major portion of the lid;
• wherein the embossing is located outwardly relative to the one or more rigidifying indentations that border the functional area;
• and
• wherein the the one or more rigidifying indentations comprise a plurality of encircling indentations with at least a first encircling indentation bordering the functional area and a second encircling indentation located proximate a periphery of the lid and extending around the periphery of the lid.