The method provided produces a bio-degradable foamed material with qualities of uniformity of mechanical and physical properties throughout the product including a foam thickness of up to one meter and a finished foam surface suitable for packaging applications. The parameters for producing such a product are selected from a range of variables which includes wall thickness, mold material, use of a susceptor and the type and composition of a susceptor, the number and arrangement of magnetrons and mold shape. Complex shapes produced by the process are also disclosed.