May 2012
Futae-kōzu pattern
After a few distractions (like doing some actual paying work), I managed to get some work done on the kōzu pattern for the book. The photo shows one of the completed kōzu sections of the panel. The multiple layers of the crosses to me really highlights the beauty of this pattern. I would have preferred a greater interval between the rows of crosses, and in principle, this interval should be at least the same size as the crosses, but because I designed this purely for instructional purposes, and I also wanted the multiple cross layers, and to include the futae-shokkō pattern at the bottom, I had to bring them a little closer than I would have liked. Because there is a clear differentiation between the crosses, though, this is a reasonably satisfactory design.
While there is a little design flexibility with the kōzu pattern, there are some design and dimensional principles that should be adhered to, and I cover these in detail in the book. And although I don’t make the other kōzu patterns, I also give diagrammatic examples of the hitoe-kōzu, mie-kōzu, and another way of making the futae-kōzu involving slightly simpler cuts but more kumiko.
For shoji made with this pattern to be anywhere near economically feasible, the work processes have to be streamlined. That means that when making the cuts, the same cut should not be repeated (unless, of course, there are too many kumiko to be manageable for a single cut by hand). Repeating the same cut simply means that additional time has been spent and wasted lining up, securing and cutting the kumiko.
What I mean by this is that, say, when making a joint cut in the vertical kumiko to fit a horizontal kumiko, all the vertical kumiko that require that joint in the same position to house that horizontal kumiko should be cut at the same time. This also applies when making the cuts in the horizontal kumiko for the vertical kumiko. In the book I detail the optimum cutting sequence for both vertical and horizontal kumiko.This pattern is time-consuming, but it should not take a long time.
This pattern may seem simpler than the futae kaku-tsunagi I introduced in Book 1 and show here, but the cuts and assembly are, in my opinion, more complex. I also detail a suggested assembly sequence (the one I use) to help the process for the kōzu pattern flow more smoothly.
It’s now on to completing the shoji, finishing the writing part, then designing the next shoji, which will be a step up from the naka-nuki shoji shown here.

While there is a little design flexibility with the kōzu pattern, there are some design and dimensional principles that should be adhered to, and I cover these in detail in the book. And although I don’t make the other kōzu patterns, I also give diagrammatic examples of the hitoe-kōzu, mie-kōzu, and another way of making the futae-kōzu involving slightly simpler cuts but more kumiko.
For shoji made with this pattern to be anywhere near economically feasible, the work processes have to be streamlined. That means that when making the cuts, the same cut should not be repeated (unless, of course, there are too many kumiko to be manageable for a single cut by hand). Repeating the same cut simply means that additional time has been spent and wasted lining up, securing and cutting the kumiko.
What I mean by this is that, say, when making a joint cut in the vertical kumiko to fit a horizontal kumiko, all the vertical kumiko that require that joint in the same position to house that horizontal kumiko should be cut at the same time. This also applies when making the cuts in the horizontal kumiko for the vertical kumiko. In the book I detail the optimum cutting sequence for both vertical and horizontal kumiko.This pattern is time-consuming, but it should not take a long time.
This pattern may seem simpler than the futae kaku-tsunagi I introduced in Book 1 and show here, but the cuts and assembly are, in my opinion, more complex. I also detail a suggested assembly sequence (the one I use) to help the process for the kōzu pattern flow more smoothly.
It’s now on to completing the shoji, finishing the writing part, then designing the next shoji, which will be a step up from the naka-nuki shoji shown here.

Comments
Kōzu cuts
15 May 2012 Filed in: Book
I finished the frame pieces and tsukeko, and they’re safely tucked away until the final finish planing before assembly. Today I started on cutting the kumiko joints for the kōzu. The photo shows the kumiko for one kōzu panel.
You can see by the number of cuts for just one of the panels how much work is involved in this pattern. This, though, is only the preparatory work. From here, I will assemble the main vertical and horizontal kumiko, then trim the shorter kumiko and cut the mitres.
The kōzu was a popular pattern for shoin shoji - the attractive decorative shoji in the shoin-zukuri style of architecture - but it was largely limited to nobility and the upper echelons of the samurai warrior class. It was this kind of work and the skills needed to make it that led to the growth of the sub-branch of shokunin within the tategu trade known as kumiko shokunin. They are the shokunin who specialise in the intricate kumiko patterns.

You can see by the number of cuts for just one of the panels how much work is involved in this pattern. This, though, is only the preparatory work. From here, I will assemble the main vertical and horizontal kumiko, then trim the shorter kumiko and cut the mitres.
The kōzu was a popular pattern for shoin shoji - the attractive decorative shoji in the shoin-zukuri style of architecture - but it was largely limited to nobility and the upper echelons of the samurai warrior class. It was this kind of work and the skills needed to make it that led to the growth of the sub-branch of shokunin within the tategu trade known as kumiko shokunin. They are the shokunin who specialise in the intricate kumiko patterns.

Started the kōzu
09 May 2012 Filed in: Book
I finally managed to get a start on the next shoji and patterns for Book 2. I dimensioned the rails and stiles yesterday afternoon, and all this morning was spent cutting and dimensioning the kumiko. The following photo shows about four hours’ effort (the timber is Huon pine).

The kumiko mitsuke is 4.0 mm exactly; not 3.9 or 4.1 mm. In fact 0.1 mm in shoji and kumiko work is a massive size. Every one of these kumiko has to be checked after I finish preparing it to the correct thickness. I use a pair of digital callipers for this.
In this shoji there are 30 vertical kumiko, and 68 horizontal kumiko. I also make up a reasonable number of spare kumiko in case disaster strikes.
In the futae-kōzu part, there are 15 vertical and 27 horizontal kumiko, and also 64 mitre joints to cut for each panel. So there are 128 kumiko mitres to cut, and that’s just for the kōzu pattern. There are many more mitres to cut for the futae-shokkō patterns on the bottom. Each one must have exactly the right amount of tension, otherwise the overall piece can look very ordinary indeed. I can assure you that by the time you finish making this shoji, you will certainly be sick and tired of mitre joints.
The kōzu is not a particularly difficult pattern to make. The futae-kōzu design here essentially builds on the kawari-gumi shoji and futae kaku-tsunagi pattern we tackled in Book 1. It is, however, a very time-consuming pattern when done properly, and this is what makes it so expensive.
It is, though, one of my favourite patterns. And it can be adjusted and used in a broad range of work, not just shoji.

The kumiko mitsuke is 4.0 mm exactly; not 3.9 or 4.1 mm. In fact 0.1 mm in shoji and kumiko work is a massive size. Every one of these kumiko has to be checked after I finish preparing it to the correct thickness. I use a pair of digital callipers for this.
In this shoji there are 30 vertical kumiko, and 68 horizontal kumiko. I also make up a reasonable number of spare kumiko in case disaster strikes.
In the futae-kōzu part, there are 15 vertical and 27 horizontal kumiko, and also 64 mitre joints to cut for each panel. So there are 128 kumiko mitres to cut, and that’s just for the kōzu pattern. There are many more mitres to cut for the futae-shokkō patterns on the bottom. Each one must have exactly the right amount of tension, otherwise the overall piece can look very ordinary indeed. I can assure you that by the time you finish making this shoji, you will certainly be sick and tired of mitre joints.
The kōzu is not a particularly difficult pattern to make. The futae-kōzu design here essentially builds on the kawari-gumi shoji and futae kaku-tsunagi pattern we tackled in Book 1. It is, however, a very time-consuming pattern when done properly, and this is what makes it so expensive.
It is, though, one of my favourite patterns. And it can be adjusted and used in a broad range of work, not just shoji.
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