General Production Process
Casting Creating forms by melting
First you surround a form made with wax with a casting material, mixed with sand or clay, to make a mold. Then you heat the mold until all the wax melts out of it (the lost wax method). Next, you pour molten metal into the mold, and when it cools you destroy the mold. Since the wax that originally filled the mold disappears, you are left with a metal object with the same shape as the original wax one.
A mixture of clay and sand is shaped by rotating a board with a cutout outline that is a cross-section of the final shape. This technique is used to make tea kettles for the tea ceremony, temple bells and other circular, symmetrical objects.
After removal from the mold, a kettle can be heated and painted with lacquer and ohaguro (a coating used in the old days to blacken one's teeth) to produce a uniquely beautiful finish.
First, you make a form with clay, then you use plaster to create a mold with the same shape. Cover the mold with casting material, make a copy its form to create an outer mold, and then create a slightly smaller inner mold. Pour molten metal into the interstice between the outer mold and the inner mold, and remove the metal from the mold after it cools.
Smithing Creating forms by beating
On an indented section of a wooden stand, a flat piece of metal is beaten with a wooden mallet so it can be bent. After this, variously shaped iron bars known as ategane are poked toward the wooden platform to create a form gradually. A piece of metal must be beaten tens of thousands of times to create a single finished work.
Metal carving Applying decorative designs
Different sorts of chisels can be used to create various designs on the surface of metal. The basic technique is one where a chisel with a V-shaped tip is used to carve lines into the metal. In another technique a triangular-tipped chisel is used to make a series of fine lines, and in another an especially sharply pointed chisel is used to cut all the way through the metal.
In this technique, lines are carved into the surface of metal and different metals are inlaid in the carved-out lines, with the differences in the color and texture of metals creating the design. There are a variety of techniques such as hirazogan (flat inlay), in which flat sheets are inlaid to be the same height with the ground surface; takaniku zogan (high mounted inlay), where material is set on a high-relief metal ground; and nunome zogan (texture inlay), in which thin metal leaf is hammered into a carved pattern.
Starting with a sheet of metal, you use a wide range of implements and beat it from both the front and the back many times to create a three-dimensional form. Some are highly pronounced three-dimensional forms, while others are shallow reliefs like those seen on brooches and kimono sash ornaments.
"What Are Traditional Crafts? -A Guidebook to Seeing, Learning, and Enjoying-"
Edited by the Japan Kogei Association Eastern Branch. Published by Unsodo ／ List of works English translation: Kazuko Todate (Art critic / Art historian)
Famous local brand
Nambu Tekki ironware is produced and sold mainly in the cities of Morioka and Oshu in Iwate Prefecture. It is appreciated for the way its texture and character develops over many years of use.
Takaoka Doki copperware is produced and sold in Takaoka City, Toyama Prefecture. Its key feature is the attractive chased decoration known as chokin, created by using a variety of different chisels to cut lines, planes, and patterns.