Chokin(彫金) and Uchidashi (打ち出し)

Chōkin and Uchidashi Tools

Chōkin and Uchidashi are the Japanese counterparts to the western art of Chasing and Repousse. While uchidashi corresponds to the art of repousse, chōkin is more of chasing and engraving techniques incorporated together to serve a function to uchidashi  as chasing is to repousse.

Chokin(彫金)

While Chōkin in a general sense refers to the art of metalworking as a whole, it is also generally translated as chasing, so when the term  chōkin is used it is mainly to refer to chasing unless stated otherwise. The characters that describe chōkin (彫金) when translated literally can mean ‘metal carving’ or ‘metal engraving’ which in a way describes the action involved in the art , the usage of tagane being hammered into the metal to shape it very much resembles carving or engraving.In a general sense, chōkin  encompasses other branches of the metal arts such as hammering or tankin (鍛金) , metal casting or chukin (鋳金) ,hairline engraving or kebori, openwork or sukashibori (透彫) and repousse or uchidashi ((打ち出し). Chōkin, together with kebori  is a finishing art while tankin, chukin and uchidashi are forming arts. This can be seen in the tools used specifically for chōkin  namely the tagane or chisels. Chōkin tagane are generally small in size and shape are namely responsible for the fine finishes and detail seen in Japanese metalwork most notably the tsuba(sword hilt guard) and Meiji vases. 

Uchidashi (打ち出し)

Uchidashi has gained a reputation in the West as being known as the Japanese version of chasing and repousse. This is partially true but uchidashi  works in concurrent with chōkin  just as chasing is to repousse and uchidashi itself is a subset of chōkin . In the traditional Japanese sense of chōkin , uchidashi is the part where a base is formed on a sheet of metal(by pushing the metal and forming a crude relief) from the underside, such that a base is created from which one could use chōkin  to further refine the base into a proper form.This can be seen through the shape and design of the blanks used to create uchidashi tagane. Uchidashi tagane blanks are large and they have a large area designed for creating pushers and forming tools most notably the dashi tagane or a repousse pusher.Most uchidashi tagane resemble their western repousse counterparts. However the technique of uchidashi differs from the technique of Western chasing and repousse in the sense that while repousse is used to define form which will be cleaned up with chasing, uchidashi begins by pushing out a rough area to create a bulge in the metal only to sculpt from that bulge.