Welcome.This site is a directly managed online-shop of OKA CRAFT. We specialize in Japanese puzzle boxes (Himitsu-Bako)!

4.2 sun puzzle box

Today, I cut the natural wood panels for two types of Japanese puzzle boxes and prepared them for drying. Since these panels are made from natural wood, they need to be thoroughly dried. Natural wood tends to shrink significantly, so if they are not fully dry, gaps may form in the lid part of the box after it is assembled, or the mechanism may not work smoothly. As shown in the photo, I have prepared three types of panels this time. All of them will be used for the top and bottom surfaces of the boxes.

As seen in the photo, the wooden blocks I prepared yesterday have been flattened into panels and will be left to dry for a while. This process not only removes the natural moisture from the wood but also helps to dry the glue used when assembling these pieces. Since the glue is water-based, it contains a lot of moisture. While taking this photo, I noticed that I didn’t use any Hoo wood this time. It’s not really a problem, but since I’ve been using ho wood frequently recently, it seemed a bit unusual😅 The black line visible in the center of the photo is not katsura jindai wood, which I sometimes use, but rather walnut wood. There’s a variety of walnut wood with a coarser grain that I find less suitable for side panels of box, but because its color is darker than usual, I was able to incorporate it here as part of the design.

After finishing that task, I started working on a 4.2-sun puzzle box. Today, I began with the first steps of constructing the box, making the frame and parts and assembling them (photo). It's hard to tell at first glance, but the 4.2-sun box is slightly larger than the 4-sun box. As I've mentioned before, I began making this size because I wanted to create a more stable version of the 4-sun puzzle box. The 4-sun box is a popular size with a convenient size for customers, especially in Japan, but I've always felt that the standard 4-sun size could be a bit unstable in terms of the mechanism.

This is just my speculation, but I believe the current 4-sun boxes were designed more for the convenience of the craftsmen. The 4-sun box sells well, but for its size, the price is relatively low. Because of this, the makers tried to minimize the size and reduce the thickness of the panels to cut down on costs, which weakened the structural integrity of the box. The 4.2-sun box I started making is designed to address those issues by using thicker panels and slightly larger dimensions. Even now, when I make the standard 4-sun size, I often struggle with its inherent structural fragility due to the smaller size.
However, the name "4.2-sun Japanese puzzle box" can be confusing when compared to the 4-sun box, so I’m considering whether there might be a better name for it😅