Stamping of a flat sheet into a hollow, seamless item involves tensile, frictional, bending, and compressive effects. A quantitative analysis of stresses developed in the sheet during such a “deep drawing” operation is presented indicating that the maximum depth of draw depends on the ratio of tensile stress and compressive yield stress in the plane of the sheet. Several materials are examined and their performance in deep drawing analyzed in terms of proposed criteria for deep drawing. Techniques are discussed which can be used to increase the depth of draw of polymeric material.