Abstract: This invention provides a self-supporting container (10; 110; 210; 310) having at least one wall (36; 336), a base (52; 152; 252; 352) and a top (50; 350). The top has a closable spout (54) whereby the container is suitable for storing and transporting materials such as a drinks and other liquids. The wall is made of plastics material and includes at least one wall air chamber (26; 226; 326). The base has at least one base air chamber (84, 86), the at least one base air chamber having a dimension (2d) which is greater than a dimension (w) of the base whereby the base of the container is concave. The concave shape of the base makes the container more stable in use. There is also provided a blank for making the container, and a method of manufacturing the container blank.