Abstract: A liquid container comprises a rigid planar material defining first and second faces interconnected by at least two connecting edges, and each face has an inner surface and an outer surface. The container is characterised in that it is configured to be converted, upon application of substantially opposing forces to two sides of the container, from a planar configuration, in which the inner surface of the first face is substantially adjacent to the inner surface of the second face, to an open configuration, in which the inner surfaces of the first and second faces are spaced apart and which, in combination with the at least two connecting edges, define a volume therebetween for containing liquid.