Abstract: A method of forming a metal mold or die from a model of the mold contours. A workpiece for the mold is coated with a material which is resistant to an acidic etchant, and is then immersed in the etchant and brought into contact with a template for the metal mold or dies. Those portions of the coating contacted by the template are displaced until the template contacts the surface of the workpiece. The template is then withdrawn to permit the echant to etch any portions of the workpiece exposed by displacement of the coating. The process is progressively repeated until the surface of the workpiece conforms to any contouring of the surface of the template.