What We’re Talking About When We Talk About Japanese Joinery

What We’re Talking About When We Talk About Japanese Joinery

Joinery, in a basic description, is the interlocking cutouts used to connect different pieces of wood. Invented before the use of modern adhesives or metal fasteners, joinery is an ancient part of woodworking, but to this day it has advantages over more modern techniques.


For example, wood is a constantly changing, moving material – humidity and seasons and time will cause the wood to expand and contract. Metal hardware, as a static material, can be insufficient to hold that movement. Conversely, adhesives may be so restrictive of the natural movement that they may cause the wood to split or bow, over time.  Joinery is the art of using wood connections to contain these changes in the material, and using wood-on-wood as the structural fastening will also allow for some “play” in the material as it wants to shift.


In Japan, the tradition of joinery is rooted in architecture, and elevated to the highest level of craftsmanship. Japanese woodworking has very sophisticated and intricate approaches to building joints and connections, and this work is done by hand with the use of saws, chisels and planes. The tradition around joinery in Japan surpasses what was developed in the West, where hardware and power tools were more emphasized.

The influence of Japanese joinery in our furniture stems from my work in timber frame building in the San Francisco Bay Area with the company Joinery Structures Inc. Since my woodworking training comes from building Japanese style homes and structures, when I am making furniture I often think “if this were a house, how would we build it?”


The joinery is always tailored to the specific connection in the furniture, aware of the movement of wood over time, the stresses on the structure of the piece, and the specificity that the joinery can lend to the form.

I often use “exposed” joinery, for example, the through-mortise-and-tenons that reveal the legs of our stools or tables through the seat or table top. Using exposed joinery demands a high level of detail and precision and is unforgiving for its visibility. We see exposed joinery as a way to invite an experience with the process that can add to the beauty of the work.


But, it is also common in traditional Japanese work to go to great lengths to conceal the joinery employed — giving an impression of seamlessness that, without relying on adhesives and hardware, demands exceptional workmanship and mastery. Depending on the application it can often be more demanding to conceal the joinery than expose it. Sometimes its what isn’t shown that gives the piece its magic.

In our UKB Chair the complex joinery we designed to make the form possible is totally concealed — inspired specifically by the philosophies of traditional Japanese craftsmanship.


Our interest in the design of this spare and streamlined form is to invite an instinctual interest and curiosity. Doesn’t this chair have somethings missing? There is no bottom cross brace, for example. The form feels unusually light or paired down. This is possible because of the additional stability from the joinery.


In the end, I use joinery because it is a language within woodworking I am drawn to. I use it because it is engaging to make, challenging, but poetic. I use joinery out of respect and interest in the wood itself, and all that wood is capable of as a material.