Yosegi zaiku (mosaic woodwork) (寄木細工)

Yosegi zaiku is a traditional craft often seen at souvenir shops in the town of Hakone as well as in countries overseas. It has a history of about 200 years. It is a technique in which traditional Japanese patterns, such as shima (stripes), ichimatsu (checks), sayagata (gossamer-figured pattern), asanoha (stylized hemp leaf pattern), masu (square checks), yabane (fletched arrow pattern) and seikaiha (pattern of waves in blue ocean), are created by yosegi (wooden mosaic) work.

The Tokyo-Hakone collegiate ekiden race, held annually in Japanese New Year, is known for presenting a trophy made of yosegi zaiku to the winning team of the first leg of the race.

Wood preparation method

The materials used are brush wood pieces such as Japanese bigleaf magnolia, bitterwood, cherry, cornel and tamo (Fraxinus mandshurica or Fraxinus sieboldiana, a type of ash) that are found throughout Japan, as well as jindai (something that was buried underground or submerged in water for many years) such as katsura (Japanese Judas tree) that fell, buried in soil and then dug out several hundred years later. Since the trees on Mt. Hakone are planted ones, they are not very suitable. For material selection, those with less red color are used for koyosegi (small yosegi), and the strongly red-colored ones are used for muku (solid color). The wood pieces are cut across the grain, adjusted with a hand plane, then cut along the grain until they are 3 to 4 mm in thickness. Strongly warped or curved materials cannot be used. The wood pieces are thinned to a finished thickness of 2.5 to 3.65 mm with a power plane.

Mokuzogan (wood inlay) technique

First, a unicursal pattern is selected. The saw has to start from a pilot hole and end with the pilot hole.

Commercially sold wooden letters are cut with a jig saw. Circular pieces with less curvature are inlaid by tilting the surface plate by the thickness of the blade. This method is applied to create mokuzogan work. Spring plates are split with a chisel to make a saw. Furthermore, each blade is made with a special file.
Finally, the backside is cut off to make a fine blade that is almost like a thread,
The piece to be inlaid is bonded onto the pattern on the base piece, and when the surface plate is tilted and ground, the inlay piece fits precisely into the base piece. The wood shavings are shaken off and the inlaid piece is glued together using a brush and hide glue that has been heated electrically. This process is repeated to inlay the pieces for Mt. Fuji, sansui (landscapes will hills and rivers) and naya (barn).

Manufacturing process

The technique of processing the wooden mosaic pieces to a finished woodwork product is called "muku zukuri" (making muku). Muku pieces can be bonded with various wooden materials if the cross-sectional area is large. Large striped blocks can be made into round trays, guinomi (large sake cups) or natsume (containers for storing green tea leaves or powdered green tea) using a woodworking turner or a lathe to create a beautiful, three-dimensional curved surface. Materials that are layered with yosegi woodwork at the surface can also be applied to the floor wood of wooden floor. In the case of koyosegi, wooden bars of rectangular and triangular cross-sections are made using a jig that can be slanted. This ends the kidori stage.

Multiple pieces of various types of wood with different colors are gathered together and bonded with glue to create a seed plate with a geometric pattern.

In the case of asanoha pattern, three lines are inserted into a triangle to make a triangular yosegi unit pattern. Yosegi pieces shaped into a hexagon are adjusted and trimmed flat at the ends, and the whole assembly is put into a template and pressure is applied using a vice. Finally, this step ends by shaping the piece into a rhombus.

Next is the oyose step. In the oyose step, quality of the materials is determined based on each pattern unit, and the pieces are made into koyosegi with a good balance.

Surface of the seed plate that is thinly shaved is called a "zuku piece." Zuku pieces are bonded onto the surface of other woodworking products such as wooden boxes, and they are used for appreciating the pattern and the motifs. This technique is called "zuku bonding." Yosegi, such as koyosegi, sansui and daimyo gyoretsu (feudal lord's costumed procession), or another inlay work is inlaid with wood, then moistened zuku plate is shaved with a plane. However, because of the difference in how the wood is shaved, hard wood and soft wood cannot be combined. After shaving, a vice is used to apply pressure, then it is prevented from drying and then lined with paper. This is now ready for zuku bonding.

Products

A technique called mokuzogan inlay work is used, for example, when inserting a shape of a fan using a curved line within an ichimatsu pattern. Others include cigarette cases in which the curved drawer contains a piano wires, that are designed to open like a wooden shutter, make noise. The shutter section is mokuzogan wood work and the sections around the box are made with zuku pieces. Also, boxes called "himitsubako" (secret boxes) are famous, which are boxes that are hard to open because of the sliding mechanism made with wooden pieces. Recently, there are products, such as Hello Kitty dolls, made jointly with yosegi woodworking and a turner.