Mokume-gane
Mokume-gane (木目金) is a Japanese metalworking procedure which produces a mixed-metal laminate with distinctive layered patterns; the term is also used to refer to the resulting laminate itself. The term mokume-gane translates closely to 'wood grain metal' or 'wood eye metal' and describes the way metal takes on the appearance of natural wood grain.[1] Mokume-gane fuses several layers of differently coloured precious metals together to form a sandwich of alloys called a "billet." The billet is then manipulated in such a way that a pattern resembling wood grain emerges over its surface. Numerous ways of working mokume-gane create diverse patterns. Once the metal has been rolled into a sheet or bar, several techniques are used to produce a range of effects.
Mokume-gane has been used to create many artistic objects. Though the technique was first developed for production of decorative sword fittings, the craft is today mostly used in the production of jewelry and
History
Origins
First developed in 17th-century
To meet this demand,
The early components of mokume-gane were relatively soft metals and alloys (gold, copper, silver, shakudō, shibuichi, and kuromido) which would form liquid phase diffusion bonds with one another without completely melting. This was useful in the traditional techniques of fusing and soldering the layers together.[3]
Over time, the practice of mokume-gane faded. The
Adoption of mokume-gane in the West
20th-21st century development
By the mid 20th century, mokume-gane had fallen into heavy obscurity. Japan's movement away from traditional craftwork, paired with the great difficulty of mastering mokume-gane, had brought mokume-gane artisans to the brink of extinction. It reached a point where only scholars and collectors of metalwork were aware of the technique.
Present day
Today, jewelry, flatware, hollowware, spinning tops and other artistic objects are made using mokume-gane.[2]
Modern processes are highly controlled and include a compressive force on the billet. This has allowed the technique to include many nontraditional components such as titanium, platinum, iron, bronze, brass, nickel silver, and various colors of karat gold including yellow, white, sage, and rose hues as well as sterling silver.[3] At the Santa Fe Symposium, a major annual gathering of jewelers from around the world, there have been several papers presented on new, more predictable, and more economic, methods of producing mokume-gane materials, along with new possibilities for laminating metals such as the use of friction-stir welding.
Techniques
Liquid phase fusion (historic)
In liquid phase fusion, metal sheets were stacked and carefully heated; the solid
Soldering (brazing)
In attempting to recreate the appearance of traditional mokume-gane, some artisans tried brazing layers together. The sheets were soldered using silver solder or some other brazing alloy. This technique joined the metals, but is difficult to perfect, particularly on larger sheets. Flux inclusions could be trapped or bubbles could form. Commonly, imperfections need to be cut out, and the metal re-soldered. Ultimately the brazed sheets do not display the ductility and work-ability of diffusion bonded material.
Solid-state bonding (contemporary)
The modernized process of solid-state bonding typically uses a controlled atmosphere in a temperature-controlled furnace. Mechanical aids such as a hydraulic press or torque plates (bolted clamps) are also typically used to apply compressive force on the billet during lamination. These provide for the implementation of lower temperature solid-state diffusion between the interleaved layers, thus allowing the inclusion of non-traditional materials.[3]
Development of the mokume-gane pattern
After the fusion of layers, the surface of the billet is cut with chisel to expose lower layers, then flattened. This cutting and flattening process will be repeated over and over again to develop intricate patterns.[4]
Coloring
To increase the contrast between the laminate layers, many mokume-gane items are colored by the application of a patina (a controlled corrosion layer) to accentuate or even totally change the colors of the metal's surface.
Niiro patination and rokushō
One example of a traditional Japanese patination for mokume-gane is the use of the niiro process, usually involving rokushō, a complex copper verdigris compound produced specifically for use as a patina. The piece to be patinated is prepared, then immersed in a boiling solution until it reaches the desired color, and each element of a compound piece may be transformed to a different color. Historically, a paste of ground daikon radish was also used to prepare the work for the patina. The paste was applied immediately before the piece is boiled in the rokushō to protect the surface against tarnish and uneven coloring.[4]
Similar laminates
In an accidental but parallel development,
See also
- Mokume-gane titanium rings – Jewelry rings or bands mainly of titanium
- Pattern welding – Swordmaking technique
- Damascus steel – Type of steel used in Middle Eastern swordmaking
References
- ISBN 0-9651650-7-8.
- ^ a b c "About Mokume Gane". andrewnycedesigns.com. 2002. Archived from the original on 14 June 2011. Retrieved 2015-02-10.
- ^ a b c d e f Binnion, J. E. & Chaix, B. (2002). "Old Process, New Technology: Modern Mokume Gane". Archived from the original (PDF) on 2009-08-29. Retrieved 2007-01-26.
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(help) - ^ a b c Pijanowski, H.S. & Pijanowski, G.M. (2001). "Wood Grained Metal: Mokume-Gane". Retrieved 2007-01-26.
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(help) - ISBN 0-8109-4273-9.
- ^ Norio Tamagawa
External links
Media related to Mokume-gane at Wikimedia Commons
- "Can you make copper & nickel Damascus?!? Mokume-gane," You Tube video showing the attempt of making a combined metal of copper and nickel, https://www.youtube.com/watch?v=8XgDHIx9LvQ (April 18, 2018), Retrieved December 15, 2018