In general, all Bogu is made in something of a similar way, with the majority of the Futon being made from layers of cloth, wool and felt, wrapped in natural cotton and reinforced with leather. The materials used for this reinforcement play a large role in both the appearance and the durability of the Bogu set. The biggest difference is made by the Hari (covering) which is used to reinforce the surface of the Futon. The main materials used for this are as follows:
Orizashi
This is where the Futon is covered with thick cotton, similar to the material used for the Kendogi. This is cheaper than using genuine leather, and has the advantage of being flexible and quick-drying, making it well suited to hot climates. It is not as durable as leather, however, and it doesn’t offer the same prestige as genuine deerskin. In any case, Orizashi Bogu is becoming more and more popular, as it is a great way to save cost on a good-quality Bogu set.
Synthetic Leather
Synthetic leather has been used for some time now as a substitute for genuine deerskin. Originally it was inferior by a long way, and was used only on the lowest-level Bogu sets. However, with improvements in technology, modern synthetic leathers which have been especially produced for use in Bogu – such as ‘All Japan Shin-Leather’. These are almost indistinguishable from real deerskin in terms of appearance, and are much cheaper to produce. Unfortunately, they do still have downsides… Synthetic leathers do not hold the dye the same way as genuine deerskin does, and over time changes color differently. Thus it does not produce the well known ‘faded blue’ look that Kendo practitioners have come to love. Further, although modern synthetic leathers have improved a great deal since their introduction into Bogu construction, they still do not quite compete with the outstanding durability offered by genuine deerskin. Having said this though, owing to the high cost of genuine deerskin, modern synthetic leathers allow us to make great quality Bogu at reasonable prices – making quality affordable, to practitioners of all levels.
Cow Leather
Like synthetic leather, cow leather has been used as a substitute for deerskin for some time, and in general offers a very similar appearance. However, its popularity in Japan has decreased greatly in recent years, as modern synthetic leathers have surpassed the positive qualities of cow leather for use in the construction of Bogu. Although cow leather offers excellent durability, it does not react well to moisture, becoming stiff when drying out – making the Bogu set feel somewhat cumbersome. Further, it does not take to the dye as well as deerskin, making it turn somewhat grey, as oppose to faded blue, over time.
We can use cow leather as a special customer's request, but normally we do not use it as a raw material as we use Orizashi, Clarino or Konkawa.
Konkawa (Genuine Indigo-dyed Deerskin)
Ever since the early days of Bogu construction, genuine Japanese deerskin has been favored for its flexibility and durability for reinforcing the Futon. Deerskin reacts well to moisture, remaining supple and flexible after drying, and it also takes the genuine Aizome (indigo-dye) perfectly – allowing it to fade naturally over time. Further, of all the materials used in the construction of Kendo Bogu, deerskin provides the best durability, helping the Bogu last for decades of frequent use. Unfortunately, preventing Konkawa from being the undisputed champion of materials for Bogu construction is its high price, making deerskin reinforced Bogu sets somewhat pricey. Further, although it is more durable than Orizashi, it does not dry as quickly, so it is not necessarily the best for consecutive use, particularly in humid environments.
Goku-Jou (literally 'extremely superior') Konkawa, is the finest cut of deerskin available, and is extremely soft and flexible. Despite this though, it has and extremely good level of elasticity making even more durable than standard Konkawa.
Mousen
Mousen is the felt that is inserted between the layers of wool padding inside the Futon. It does not appear in some low-quality cheaper sets, and there are several styles and types. Good quality scarlet Mousen is used in many modern hand-stitched Bogu sets, which is very flexible and offers good padding. However, the very best quality Mousen is known as 'Kodai-Mousen', which Mousen which is made in the traditional way, by hand from animal hair. Kodai-Mousen is very rare and expensive, but thanks to the extra air-particles that remain inside - due to the traditional construction - using it in the Futon gives an unrivaled feeling of flexibility and protection.
Inside of a hand-stitched Bogu Futon.
Kazari Ito
Kazari Ito is the thick, braided rope-like decoration that appears on several areas of the Kendo Bogu. It serves the main purpose of decoration, and is available in several colors, though it also serves more practical purposes in some cases – such as separating the chamber of the Atama (fist portion) of the Kote.
Chikawa or Chikaragawa
This is leather backing that is applied to the Futon, to conceal and protect the reverse side or friction areas. It is only found in places that are particularly susceptible to wear, such as over the reverse stitching of the Kazari-Ito on the Mendare. This is usually done in leather similar to other reinforcements on the Bogu, though in some cases there are options to change this.
The Mimikawa is also part of the Chikawa reinforcements that can be made of different materials (Clarino, Deerskin, etc.). Sometimes can be customizable. but usually is predetermined by the Bogu set model.