What is the purpose of polishing Japanese swords, which differs from that of other blades?
There is no accurate way to know the origins and development of the art of Japanese sword polishing, due to the nature of the repeated sharpening process over time.
However, a description of Japanese sword polishing is found in the Engishiki, a mid-Heian period code describing annual court ceremonies, and two names of "Togishi" are mentioned in the Kanchiin Honmeizukushi, a sword book of the Kamakura period. This suggests that polishing is a process used in Japanese sword making since ancient times and that there were craftsmen specialized in this field.
The purpose of sharpening knives other than Japanese swords, such as those used in everyday life, is to restore or improve their edge. Japanese swords, which have a long history of use as weapons, were also sharpened to fully demonstrate their ability to pierce and cut.
The purpose of polishing swords does not end there. After the Meiji period (1868-1912), when the samurai society came to an end, Japanese swords became objects of appreciation as "works of art" rather than as armor. In other words, not only the strength of the sword in terms of performance, but also the beauty of its appearance was sought after and appreciated.
The various elements that make a Japanese sword beautiful include many subtle things that cannot be seen at first glance. One of the goals of polishing Japanese swords is to bring out as many of these features as possible.
Practical aspects of Japanese sword polishing
What is the history of Japanese sword polishing until today?
It is said that the art of Japanese sword polishing has been passed down to the present day largely through the achievements of the Honami family, whose founder was Honami Myohon, who served Ashikaga Takauji as a Dobo-shu (a person who served alongside the shogun or feudal lord and was responsible for artistic and miscellaneous affairs) during the Northern and Southern dynasties.
The Hon'ami family has been involved in the family business of sword care, polishing and evaluation for generations. They served the Toyotomi and Tokugawa families after the Ashikaga family, and were responsible for various tasks related to swords belonging to the shoguns.
The Hon'ami family was valued in the field of polishing. However, in the Meiji era (1868-1912), the Soke and some of their affiliated families ceased to exist. On the other hand, some of the offshoot families survived, and the present Hon'ami family can be traced back to an offshoot family whose founder was Koui, the third son of Koushin, the seventh head of the Soke family.
In addition to Kouyi, who became the eighth chief of the soke, Kouzou had several brothers, one of whom, Koji, also established a branch of the family. Koji was originally the son-in-law of the childless Kōshin, but he later left the soke himself when Kōshin had a son of his own. At that time, the world was in the Warring States period.
In the early Edo period, the second head of the Hon'ami family, Hon'ami Koetsu, who was arguably the most prominent member of the Hon'ami family, came from the Koji lineage.
Koetsu was not only engaged in the family Katana business, but also demonstrated his talent in various artistic fields, including calligraphy, ceramics, tea ceremony and lacquerware, to the point of being described as a "complete artist". This may be because Japanese swordsmanship itself is a complete art form that brings together a wide range of craft techniques, including metalwork, woodwork, maki-e and carving, as well as swordwork, and his aesthetic sense for craftsmanship naturally developed at an early age.
The Hon'ami family of the Kouyi lineage is a group of masters in the modern and contemporary world of Japanese sword polishing. We will now examine some of the major sharpeners among them.
Honami Heijuro Narushige.
His real name is Eguchi Kurajiro. He was the adopted son of Naonojo Nariou, the 14th head of the family, and a master craftsman of the Meiji era who followed in his footsteps. He invented a new technique, colloquially called "cosmetic sharpening", based on the traditional insertion sharpening practiced until the Edo period.
As the term suggests, this technique is used to make the blade pattern of a Japanese sword look white and beautiful, as if it had been invented, and has become the most common technique today. Died in 1882 (Meiji 15) at the age of 55.
His real surname is Yamamoto. He was a nephew of Seiō, but was adopted by Hon'ami Heijūrō Narushige and took over the family. At first he was called Honami Naruyoshi, but in 1911 his favorite sword master, Sugiyama Shigemaru, gave him the name Rimga.
He died in 1927, at the age of 68.
Born in 1879 (12 Meiji), son of "Kawaguchi Magotaro [Kinmei]" (川口孫太郎), who served in the Ueno Maebashi clan (Kozuke Maebashi Han: today's Maebashi City, Gunma Prefecture). His real name was Sadakichi. At the age of 18, while studying under the Hon'ami Rimga during the Seizen period, he succeeded to the name Koga, which was descended from the Komi lineage broken under the care of the Hon'ami Rimga, and took the name of the Hon'ami Mitsuyoshi. Hon'ami Mitsuho's polishing skills were of a high standard and recognized by his masters.
In 1914, he published a book entitled "Japanese Swords" in order to disseminate more widely the methods of polishing and grading Japanese swords, which until then had been considered a secret tradition. In 1955, at the age of 77, Hon'ami Mitsuhisa published his famous book entitled "The Rules and Characteristics of Japanese Swords", which still enjoys a well-established reputation as an introductory book on sword evaluation, and he passed away the same year.
Polishing procedure for Japanese swords with sharpening.
The procedure of polishing Japanese swords by sharpening can be divided into two main steps: basic sharpening and finishing sharpening. But before that, there is also a process called "forge pressing/rough sharpening", which is performed by the swordsman who produced the Japanese sword.
The main purpose of polishing Japanese swords is to shape the sword and bring out its beauty to the maximum. Therefore, in order to ensure that the blade pattern, which is the most important criterion for the beauty of a Japanese sword, is clearly visible, the sword is ground with about 7 types of sharpening stones of different sizes, alternating between the coarsest and finest stones.
This section provides a step-by-step explanation of the process, from pressing to forging, through preliminary sharpening to the final stage of Japanese sword polishing, final sharpening.
Forge pressing/old fashioned sharpening
This process is done to shape the hardened sword blade before the preliminary sharpening step of polishing. The shape and lines of the blade are determined, and the swordsman finishes the blade himself to check the final finish before sending it to the sharpener.
[Grain size] 120-220.
The coarsest grindstone used to remove red rust and to sharpen a sword blade that has been hammered (finished to a coarse grind by the sword smith) to determine its general shape.
In later work, the blade is repeatedly sharpened to a more elaborate shape while retaining the "nikuoki" (thickness of the blade except for the shinogi-ji) determined at this stage.
[Grain size] about 400
A sharpening stone used to remove the grain of the Iyoto and to adjust the details of a sword blade that is deformed.
The basic method is to use the "kiri" sharpening method, in which the sharpening stone is placed horizontally against the sword blade.
Another important process is the polishing of the blade to match the shape of the blade to the era in which it was made.
[Grain size] about 800
A whetstone used to remove the grit from the whetstone of a binsui whetstone. It is not applied to the spearhead/kisaki because it has a high sharpening effect and there is a risk of removing the excess flesh.
This work requires special attention to reduce the amount of sharpening. Here the blade is sharpened so that the grain of the sharpening stone forms an angle with the blade, called "sujikai".
[Grain size] No. 1,000-1,500.
The work with this whetstone is done in two steps: first, the blade is sharpened "osujikai" (at a more oblique angle than sujijikai) in order to remove the grain of the whetstone from the binsui whetstone.
When the grain of the binsui whetstone is almost completely removed, the next step is to polish the blade in a method called "tatsu-tsuki" (hitting the blade with a tatsu). This is a method of sharpening the blade vertically in the direction of the blade, with the grain of the whetstone aligned in an orderly fashion without any irregularities.
When making sword mounts such as sword blades and scabbards, the sword is sent to a specialized craftsman at this stage.
[Grain size] No. 2,000.
It is used to sharpen the blade of a sword by pitting the tatsu in the same way as the Nakamagura whetstone, while erasing the grain of the Nakamagura whetstone. This is the final step in the base coat sharpening process, where the pattern and surface of the blade can be seen gradually. Base coat sharpening is therefore an extremely important process that determines the final result of the blade.
The last step is called jiji sharpening, but it is a very important process because it determines the final shape of the blade.
The purpose of preliminary sharpening is to determine the shape of the sword blade and to bring out the original characteristics of the blade. Finish sharpening is to further refine the appearance of the blade so that it can be appreciated. While the only tool used for preliminary sharpening is a whetstone, although it varies in size, the final sharpening process is different and involves a variety of tools.
This process is used to polish the blade, using two types of whetstones, but differs from the preliminary sharpening process in the way it is done. The former is a delicate process in which the sword is sharpened by moving a small whetstone over the fingertip, while the latter is done by moving the sword.
The blade is polished using a 0.4 inches square of uchigumoridō, which is torn into thin 0.20 inches mm strips, and a hazuyadō, which is lined with Yoshino paper and lacquered.
The process is done by placing the blade glaze on the tip of the thumb and pushing and sliding the blade glaze over the tip of the thumb while applying the juice from the Uchigumorido to the blade to improve the glide of the sharpening stone.
The blade is polished to remove the grit from the wheel to the preliminary sharpening, and the burnished edge is then polished to a pear-shaped finish. This process is used to derive the bubbling and scent that make up the blade's pattern.
A sharpening stone called "Narutaki-do", which is less than 0,04 inches thick, is used. There are two types of sharpening stones: the "hari-ji-glaze", which is covered with Japanese paper, and the "kuraki-ji-glaze", which is not covered but crushed into small pieces with the tip of a fingernail.
The sharpeners place about ten grains on the blade and rub them upward, stopping them with the thumb. The purpose of ji-glaze is to bring out all aspects of the base iron, such as the skin pattern and jiobu. This is the last step in the polishing process using a whetstone and is also the most important step in the finishing process.
After the removal of the blade, the next process, which varies slightly from school to school, is polishing, which mainly consists of polishing and crushing the shinogi-ji and mune of the sword blade with a spatula and a polishing stick.
Before polishing, the blade is coated with "tsunoko", made from burnt deer antlers and powdered, to remove the oil from the blade, and then "ibota", a kind of beating powder made from hookworm, is applied to the area to be polished to improve the sliding of the steel polishing rod.
Then the weapon is polished with a polishing rod, but the "polishing" should not completely destroy the forged surface of the Shinogi-ji and Munemune, but should give a mirror-like shine while retaining their patterns.
A small amount of polish is left around the metal collar and the tip of the mune, and a line called "nagashi" is drawn on the metal with a polishing rod. This nagashi is a kind of signature of the polisher. The number of sinks and the way they are drawn varies according to the polisher and the school.