Abstract: A process for fabricating a plastic, which plastic is either a thermoplastic ionomer or a multiphase graft or block copolymer of the ABA, ##STR1## or (AB).sub.n wherein n is greater than 1 and wherein the polymer blocks (A and B) are thermoplastic, incompatible with one another, and have different softening points, both softening points being substantially above room temperature when using the latter class of polymers. The material is first heated to a temperature above both softening points and formed into any desired shape, then cooled and re-formed into a new desired shape at a temperature between that of the softening points of the two blocks and finally cooled to a temperature below both softening points thereby retaining the shape last achieved. When using thermoplastic ionomers the process is similar. The material is heated above the softening point of the thermoplastic backbone and plasticizers are employed to disrupt the ionic domains.