Seeking New Possibilities for
Tsugite-Shiguchi Joinery

Tsugite-shiguchi refers to processing techniques for joining two or more pieces of timber. Methods of assembly for extending timber are called tsugite, while methods intersecting timber are referred to as shiguchi. These are said to be the most important parts in work ranging from timber architecture to wood furniture, and they are required to provide both structural stability and aesthetic design. These techniques were originally introduced from the continent, however, Japan has uniquely developed them in terms of precision and the prolific number of varieties.

In recent years, uses of tsugite-shiguchi joinery techniques have become extremely limited due to changing living styles. KAI has undertaken the challenge of “Kai-Ki” – a method of shiguchi joinery that combines different materials, with the aim of seeking new possibilities for tsugite-shiguchi joinery.

Combining Wood with Acryl

In order to combine wood and acryl with high precision, first we combined wood and wood and made the tsugite-shiguchi joints as models for the acryl plate. The acryl craftsman manufactured only the shiguchi sides by faithfully following the models. On actually assembling the two pieces, we found that the acryl shiguchi and wood shiguchi parts did not fit together well, the reason being that the accuracy of acryl processing failed to match the accuracy of the woodwork. We thus tried from scratch, making from wood the shiguchi part on the other side of the acryl shiguchi. On doing so, we found that the two parts fitted together perfectly.

On viewing the resulting “Kai-Ki”, whereas the shiguchi faces are normally not visible when combining wood with wood, we found that the translucent acryl material allows light to glow in a very beautiful manner. The lightness of the acryl added softness to the elaborate and clear-cut appearance of the tsugite-shiguchi joints.

We completed six types of “Kai-Ki” over a period of six months. Oikake-daisen-tsugi (KAI-KI I1), Koshikake-kama-tsugi (KAI-KI I2), Isuka-shachi-tsugi (KAI-KI I3), Osakajo-otemon-hikaebashira-tsugite (KAI-KI I4) Nimai-hozono-sumiyoshi (KAI-KI I5), Hakosen (KAI- KI1)

Craft Appeal Derived from
Different Materials

“Kai-Ki” which combines wood and acryl, was included in the “Japan in Architecture: Genealogies of Its Transformation” exhibition staged at the Mori Art Museum in Roppongi Hills in 2018 (April 25 to September 17). It attracted much attention as the main feature in the “Possibilities of Timber Structures” exhibit that was held in the No. 1 Exhibition Room.

“I want to place them symbolically in rooms as interior decorations” “I want to scatter them as objects around my shop” “How about boldly adopting them as alcove posts in a tea ceremony room?” Also, “It would be interesting to try combining wood and iron, wood and glass” Etc.

The ability to combine roles as building members with an artistic appeal seems to have greatly expanded the possibilities and freedom of tsugite-shiguchi joinery. In the future, it is likely that experiments such as “Kai-Ki” will contribute towards passing on the techniques of tsugite-shiguchi.

Speaker: Shiro Miura Interviewer: Kanako Izumi