The World of Kumihimo and Sageo Craftsmen: Techniques, Materials, Dyeing Processes, and Modern Demand for Sword Braiding Artisans

Kumihimo-shi: The Thread Craftsmen Supporting Koshirae

The beauty of the Japanese sword is not complete with just the blade (hada / hamon). The sageo hanging from the saya, the tsuka-ito tightening the grip, the belt cord passing through the obi—these braided cords support the aesthetic harmony of the entire koshirae. The specialized craftsmen who create these are "kumihimo-shi," and they occupy a unique position within the ecosystem of koshirae-related craftspeople.

Kumihimo-shi not only create sword-specific braided cords, but often handle a wide range of braided products including obi, pouches, ceremonial garments, and decorative cords for shrines and temples. However, braided cords for swords require specifications suited to specific uses (iaido drawing motions, ceremonial wear, practical sword-bearing), making collaboration with koshirae craftspeople (tsukamaki masters, saya craftsmen, etc.) an essential specialized field.

The Techniques of Kumihimo Production—The Art of Kumidai and Braiding

At the heart of kumihimo production is a specialized tool called the "kumidai." The kumidai comes in multiple types—the maruidai, kakuidai, takaidai, and ayatakedai—each used to produce braided cords with different weaving structures.

The simplest braided cord is the "8-strand" (hachihon-gumi), in which eight silk threads cross, known as an introductory technique. In contrast, high-quality braided cords for sword sageo and hilt wrapping employ complex weaving structures using 16, 32, 64, or more threads. The more threads used, the finer and more uniform the weave, resulting in improved texture, luster, and strength.

During the braiding process, the weight of the kumidai creates tension in the threads while the craftsman's hands cross the thread positions in a steady rhythm. Within this seemingly monotonous motion, three variables—the number of threads, the crossing patterns, and tension control—interweave complexly, requiring several years or more of experience to master.

Material Selection—From Pure Silk to Modern Materials

The primary material handled by kumihimo-shi is "shokin" (pure silk thread). Silk thread has long been considered the finest kumihimo material due to its luster, suppleness, and excellent dye-taking properties. Raw silk (kiito) and twisted silk (yoriito) in particular produce different textures when woven, and are used according to the application.

Both natural dyes (indigo, madder, and phellodendron, among others) and chemical dyes are used in dyeing. Natural dye coloring is time-consuming and labor-intensive, but its deep hues and beautiful aging characteristics have irreplaceable value compared to chemical dyes. Indigo-dyed sageo undergoes distinctive color fading and changes in character with long-term use, which is highly valued by enthusiasts as "the beauty of well-used tools."

In modern times, braided cords made with synthetic fibers (polyester and nylon) have become widely popular. They excel in durability, uniformity, and low cost, and are used for iaido practice and mass-market koshirae. However, their luster, feel, and color saturation after dyeing are considered inferior to pure silk, and from the perspective of sword aesthetics, shokin remains positioned at the highest level.

Special Specifications for Sword Koshirae Braided Cords

Braided cords used in koshirae require special specifications different from general braided cords.

Sageo must have the right thickness and strength to pass through the saya's "sageo-gushi," and must be an appropriate length (typically 3–4 shaku) that does not interfere with the drawing motion. Each school has specifications for length, thickness, and color, and when a master designates these to a student, they are followed strictly.

Braided cord for hilt wrapping (tsuka-ito) is a flat-braided cord used to wrap the grip over the same-gawa (stingray skin), and must provide friction as a grip and possess strength to endure long-term use. The width, thickness, and weave density of the tsuka-ito determine the finish of the wrapping and its practicality.

Modern Demand and the Problem of Successors

Demand for sword koshirae braided cords fluctuates in line with overall sword market trends. While growth in the iaido population supports domestic demand, demand from overseas collectors and foreign iaido practitioners is increasing year by year, and kumihimo-shi who accept orders in English and Chinese have begun to appear.

However, the problem of finding successors is serious. While some kumihimo production using the kumidai has been partially replaced by machine production, high-quality sword koshirae braided cords still rely entirely on skilled handwork. Apprenticeship requires a minimum of 3–5 years, and it takes even longer to achieve stable income. Currently, there are only several dozen craftsmen throughout the country working as kumihimo-shi specializing in swords.

Kumihimo-shi technique is an important craftsman skill that influences the aesthetic completeness of the Japanese sword. In sword culture where attention tends to focus on the blade and saya, we must not forget that understanding and support for craftsmen who are "unsung heroes" like this are essential to the transmission of Japanese sword culture as a whole.