Mokume gane is one name for a metal working technique developed in Japan
approximately three to four hundred years ago, in which two or more layers of
metal are permanently joined together in alternating layers to form a stack (or
billet). In the traditional Japanese technique the bond was achieved by diffusion
welding of the layers in a charcoal forge. On this laminated billet patterns of the
different colored alloys were created by a combination of cutting, twisting, and
forging of the laminate in ways to expose the various layers. The patterned billet
was then formed into finished work by applying standard forging and fabrication
techniques.