Container and manufacture thereof

A container comprising an annular sidewall which comprises upper and lower annular peripheral edges and a lattice structure of elongate ribs interconnecting the upper and lower annular peripheral edges, wherein the lattice structure is an open framework defining a plurality of sidewall openings, and a base which comprises an annular peripheral edge which is integral with the lower annular peripheral edge of the sidewall, the annular peripheral edge of the base surrounding a base wall structure which is integral therewith, the base wall structure comprising at least one injection moulding sprue at a central region of the base wall structure, wherein the at least one injection moulding sprue is connected to the upper annular peripheral edge of the annular sidewall by the base wall structure, the annular peripheral edge of the base, the lower annular peripheral edge of the sidewall and the lattice structure of the sidewall, wherein the sidewall and the base are composed of a thermoplastic polymer and define a central concavity for packaging a product, wherein in the lattice structure in the sidewall at least some of the elongate ribs comprise elongate foam ribs, wherein each foam rib comprises opposed outer and inner unfoamed solid skins of the thermoplastic polymer on opposite sides of a central cellular foam core of the thermoplastic polymer, and wherein the container further comprises a flexible sheet which is bonded to the lattice structure to cover the sidewall openings and form a sealed sidewall surface of the container.