History of Japanese Metal Crafts
“Kinko(金工)” refers to Japanese metal crafting or craftsmen who work on metal arts, and “Kinkohin(金工品)” refers to metal crafts.
Metals and metalwork technologies were brought to Japan in the early Yayoi period around 200 BC.
Bronze and iron were used to make swords, and copper jewels and accessories with the metalwork techniques transmitted from the mainland China and the Korean Peninsula.
Metalwork such as horse harnesses or armors began in the Kofun period (about 300 to 538 AD) as well as decorations to bronze swords and mirrors.
Some of the metal works made by casting such as iron swords and axes from the Kofun period are excavated from some ruined site in Japan.
From the Nara period (710–794) through Heian period (794–1185) the casting technologies to make Buddha statues were developed along with the introduction of Buddhism.
As Buddhist arts became popular, engraving technologies were applied to decorate metal fittings of temples, and metal works were extended to crafts and art works.
On the other hand, iron was introduced to make everyday items such pots, kettles, as well as agricultural tools.
With the industrialization and mass production of metal crafts during the Kamakura period (1185 -1333) through Azuchi-Momoyama period (1568 -1600), metalwork technologies further advanced.
As a result, metal products which were initially intended only for the privileged classes were spread out to the general classes.
In the samurai society, decorations to weapons and swords became popular, and technically superior decorations were also applied to metal fittings of sword cases and sword hilts, etc.
In addition, with the development of tea ceremony culture, metal tea kettles started to be made. Many masterpieces with artistic values have remained to date.
After the Edo period (1603- 1868), metal craft techniques evolved in their unique ways, and metal crafts began to stay in place and enriched people’s life.
Major Metal Craft Techniques
There are 3 major techniques in metal crafting as shown below.
Die casting is a manufacturing process accomplished by forcing molten metal under high pressure into reusable metal dies.
A die used for casting is called “Igata (cavity)” and products made in die casting technique is called “Imono.”
Dies are made of fire-proof sands or plaster.
As mentioned in the history section of metal crafts, Buddha statues were made by die casting in which each body part was die casted and assembled to other parts to accomplish a whole Buddha body.
In addition, bronze status you see in the middle of cities, bells at temples and shrines are made by die casting and finished by coating and coloring on the surface.
Die casting is widely adopted in many areas from mass-producing industrial parts to jewels because multiple cavities can be produced by using a prototype.
Forging is a process that hammer metal with a hammer or mallet.
Metal workpieces are hit against an iron bar called “Ategane” and squeezed to be shaped.
This is a technique called “Tsuiki”(鎚起) that takes advantages of ductility of metals.
As this is a technique that shapes workpieces into 3 dimensions using the iron
plate, it is suitable for making tableware such as dishes, rice wine containers, and tea pots.
Patterns made with hammered traces called “Tsuchime” (槌目) look beautiful.
Thus, designing metal crafts by combining various sizes of Tsuchime is also possible.
A technique of hammering redly heated iron is also one of the forging techniques.
Throughout Japan, there are many production areas of forged cutlery called “Uchihamono” where traditional metal crafts are manufactured.
Cutlery made by forging and sharpening makes blades firm with long-lasting sharpness of the blades.
This is a technique of forming metal and carving a pattern using a steel tool called “Tagane”
There are various kinds of Tagane that shape workpieces into the required forms by processing the tip of bar-shaped steel materials.
The engraving technique is classified into more detailed techniques such as carving and stamping.
There is also a technique called “Zogan” (象嵌) in which channels are carved on the surface of a metal, and another metal is filled in the grooves.
Engraving is a decorative technique sometimes applied to the surface of workpieces formed in casting or forging, such as jewels, fittings of furniture or Buddhist family alters and accessories.
Representative Traditional Metal Crafts by Technique
Nanbu Ironworks (die casting)
This is ironware produced around Oshu city, Morioka city, Iwate.
They say that this technique began in the mid-17th century when a lord of Nanbu province invited Kamashi (craftsmen of iron kettle) from Kyoto to make a pot for tea ceremony.
Nanbu Ironworks were designated as the first “Dento-tekki Kogeihin” (national traditional craft by the Ministry of Economy) in 1975.
Dento-teki Kogeihin are craftworks designated by the Minister of Economy, Trade and Industry under the "laws concerning the promotion of traditional craft industries."
Nanbu Ironworks were designated as “Dento-teki Kogeihin” because it is manufactured by professional craftsmen in the traditional techniques, products that are closely related to people's daily life which are made from the abundant local resources over long time.
Currently Nanbu Ironworks are available in many forms of products such as iron pots, vases, bells, candle holders, etc.
In recent years, iron bottles and teapot with colorful coating on the surface are manufactured as well, these metal crafts are getting popular around the world including Europe, North America, and China.
Tsubame Tsuiki Doki (forging craft)
These are metal crafts mainly produced in Tsubame-city and Sanjo-city in Niigata.
It is shaped by stretching and squeezing a piece of copper plate with a hammer, thus, a distinctive feature of these metal crafts is seamless.
It was designated as “Dento-teki Kogeihin” (national traditional craft) in 1981.
The copperware industry of Tsubame Sanjo is said to have started by migrants who came from Sendai in the middle of the Edo period transmitted the technology of copper works.
With the good quality copper locally resourced from Mount Yahiko, a variety of commodities such as pots, kettles, sake bottles used to be manufactured.
They say that it would take 10 years to be able to complete seamless products out of just one copper plate by oneself, as it requires advanced techniques.
Tokyo Style Engraving
This is a traditional craftwork designated as “Dento Kogeihin” by the government of Tokyo using the technique called "Machibori" which was developed by Yokoya Somin who was from a court noble in the late Edo period.
"Machibori" is a technique of carving in which brush strokes on an ink painting are traced with carving chisels & gouges. Machibori was named by referring to Kyoto style “Iebori”
This is a unique technique developed in Japan and earned high rates in the metal crafts expo in Germany.
It is mainly produced in Adachi-ku, Bunkyo-ku, Taito-ku in Tokyo.
Other than some metal crats introduced in the earlier sections, there are approx.
1,200 traditional craft items designated as “Dento Kogeihin” (national traditional crafts) throughout Japan that includes nearly 100 of metal crafts.
It may sound confusing but Dento Kogeihin is different from Dento-teki Kogeihin.
Dento-teki Kogeihin is designated by the Minister of Economy, Trade and Industry based on the Act on Promotion of Traditional Craft Industry (Law No. 57 of May 25, 1975)
Of the 230 items of Dento-teki Kogehin throughout the country, 16 items are metal crafts.
Both Dento Kogeihin and Dento-teki Kogeihin have been contributing to maintain the traditional metal craft techniques by fully reflecting locality over a long time.