A container for receiving frangible items comprises a sheet of polymer formed into a base portion having a plurality of item-receiving cavities for supporting frangible items. A cover portion has an item-covering concavity for covering the frangible items. A first hinge portion is positioned between a first longitudinal edge of the base portion and the cover portion for rotating the cover portion onto the base portion to hold the frangible items captive in the item-receiving cavities. The first hinge portion comprises a pair of longitudinal grooves formed into the first hinge portion and extending parallel to the first longitudinal edge of the base portion, with a web defined between the longitudinal grooves, and a hinge-reinforcement wall at at least one end of the longitudinal grooves. A fold line is formed in the web and in the hinge-reinforcement wall when the cover portion is rotated onto the base portion.