Professor Otto Kümmel, who is probably well known to all collectors of Japanese art and Japanese crafts, wrote about the Japanese sword in his book "Das Kunstgewerbe in Japan", which was published as early as 1911, and explained on page 70:
"The essential element of the Japanese sword is of course the blade - and it is the blade that primarily captures the attention of the Japanese. However, the characteristics of the Japanese blade lie so deep beneath the surface and reveal themselves so little in easily grasped ornamental forms that it is almost impossible for a European to arrive at an understanding of even major differences.
All Japanese blades that rise above a certain, very low level seem at first to the European almost incomprehensibly perfect and the distinct quality levels, that any Japanese of some sword education will see at first glance, are for him almost unrecognisable.
All Japanese blades that rise above a certain, very low level seem at first to the European almost incomprehensibly perfect and the distinct quality levels, that any Japanese of some sword education will see at first glance, are for him almost unrecognisable.
Until today, little has changed in this statement. The only change in the state of affairs described by Otto Kümmel relates almost exclusively to the last sentence, which would have to be revised in such a way that in the meantime in Japan many opportunities are offered to the interested people to study really first-class blades. These include numerous good publications and literature on the various schools of swordsmiths and their regional characteristics, and the now numerous exhibitions of high-quality blades in many museums of Japan.
This is largely owed to the Japanese society "NIPPON BIJUTSU TOKEN HOZON KYOKAI". Not only does it provide opportunities for study through its own first-class publications, but in addition to its exhibitions throughout Japan and the regular meetings of its branches and subsidiaries, it continually offers those seriously interested the opportunity to take in their hands and study highly ranked blades
The purpose of this section is to give advice on how to come to an appreciation of the differences in quality.
To begin with, only one thing is important - to understand what these differences in quality are about. Perhaps the translation of the name of the Japanese society, the NBTHK mentioned above, might help. In translation, this society is called: "Society for the Preservation of the Japanese Art Sword".
This means that not sharp weapons should be preserved, but valuable historical works of art. Only from this point of view the many differences in quality can be understood. It should not be denied that here art and usability merge and that it is quite possible that the high-quality blade from the artistic point of view is also the better one in practical use.
The sword has to have both artistic and historical value, i.e., it has to be excellently forged and hardened on the one hand, and on the other hand, it needs be a good example of a particular epoch in the history of the Japanese sword. The sword has to have its own unique and outstanding characteristics in terms of form, quality and technical details. It also needs to be representative of a particular artist, school or region in which it was produced.
In order to understand these criteria, the following attempts to give a brief introduction on the characteristics of the Japanese sword and how these are determined by historical background. In addition, a chronological account of the changes in sword fighting, or rather the way of fighting, will explain how styles and forms of swords have changed over the centuries.
Characteristics of the Japanese sword can be recognized and learned, because they are obvious with some knowledge - openness, willingness to learn and eye training assumed. This knowledge has little to do with "spiritual" study, Zen Buddhism, enlightenment, kendo training or sentimentality of a samurai romanticism, but can be learned in a specific art study.
The same way to recognize and classify architecture, painting, sculpture or music by their individual characteristics, by their respective style, can be applied to the Japanese sword. You can also recognize it by its style and then classify it in terms of time and by regions, schools or even masters.
The fact that the sword is both a weapon and a work of art obscures for those, who see here only the weapon, the view of the work of art. With a sword - and this is especially true for the Japanese sword - the art does not stand out so clearly to an untrained observer.
To recognize the possible artistic value in a blade it is necessary to discuss the manufacturing process of a sword.
The work of a swordsmith begins with pre-sorting of the raw steel (tamahagane) according to different quality criteria. The raw steel are porous, almost sponge-like looking lumps of steel. The approximately fist-sized pieces can have a highly variable carbon content and therefore only partially are suitable for blade production.
It is assumed that many sword smiths up to the 15th century have produced raw steel themselves. For this purpose, iron ore, in the form of iron sand (satetsu), is smelted in a rectangular shaft furnace. Such furnaces are operated on charcoal. From the 15th century on, the smiths are starting to buy more and more raw steel and leave the production to other specialized workshops.
The pre-sorted, selected tamahagane pieces are brought to welding temperature in a charcoal fire and then fused together with the help of hammer and anvil.
Depending on what kind of forging pattern the blacksmith wants to achieve, he has to produce the suitable steel. This forging pattern hada (lit. skin) was and is different from region to region. A sword made in the province of Bizen, for example, differs significantly from a sword made in the province of Yamato or Soshu. Special forging techniques can produce the most varied hada patterns. Namely, these are e.g. itame (plank grain or plank structure), mokume (wood grain), masame (straight grain) or also ayasugi-hada (an undulating grain). The hada can be very clearly visible or very fine and dense in its structure.
A well-forged steel has clear, even appearance that extends over the entire blade. It is true, no matter how fine the steel is or what pattern the smith has created.
A badly forged blade will show an uneven hada that looks uncontrolled. In addition to this, there can be defects, holes or cracks in the steel.
The unique thing about Japanese blades, however, is their selective hardening and the design of the temper line. To produce these, a finished, forged blade is smoothed with plane irons and files and then cleanly sanded with a coarse grindstone. Then a special paste consisting of charcoal, grinding stone powder and clay is prepared and applied to the blade as a protective coating. To the still blunt future cutting edge of the blade the paste is applied very thinly (approx. 2 mm thick). This protective coat is getting thicker above the area, which is to be hardened, towards the back of the blade. Through careful shaping of the protective coating, the blacksmith now has a possibility to design future appearance of the hardening pattern of the blade itself and especially of the temper line.
This design of the hardening and the temper line (hamon) is, besides the forging pattern of the blade steel, an essential element in the production of Japanese swords. This technology is unique and is not found in any other country or culture.
The kind of hardening and the shape of the temper line have a great influence on the future strength and resistance of the blade to a shock and, of course, on the appearance of the sword as a work of art.
Once the protective coating has dried, the blade is evenly heated to hardening temperature in charcoal fire and then quenched in tempered water. Because the protective coating on the cutting edge is applied very thinly, the steel in this area cools down quickly, resulting in hardening in this area.
This process, the controlled selective hardening of the blade, determines whether the result is a blade of artistic value or "only" a weapon of little artistic value. A wrong estimation of the required hardening temperature, which is judged by the smith based on the glowing colour of the steel, can result in a deficient tempering. In the worst case, a blade gets quenching cracks, which makes it useless.
At this point, we would like to add a short text from a book published in 1733 with the following title
"The present history or current state of all nations,
the first volume,
containing a detailed description of the Great Empire
to replace the brief English report of the
Mr. Capitain Salmon
Mr. M. van Goch. M.D.
written in Dutch language,
translated into German
Published by Jonas Korte, bookseller in Altona
After discussing the state and form of government, landscape, cities, nature, agriculture and trade, the author Medicus Doctor van Goch describes on page 105 the following various techniques and crafts of the Japanese:
"They are great masters in hardening steel. Their swords can cut through our daggers without getting any scars on them. And in this they possess an art and science which is still completely unknown in Europe, that they know how to harden fine gold and silver needles in such a way that they can be used for the most difficult surgical operations, as reported above. No nation is so well versed in cutting, engraving, and tempering the sowaes, which is a certain kind of delicious black metal, of copper mixed with a little gold".
M. van Goch first describes the quality of Japanese blades and praises, without unfortunately going into detail, the processing of alloys such as shakudo or shibuichi.
After this early account, we return to the description of the blades.
For the quality of the blade as a work of art are decisive:
Only if all four components are satisfying and pleasing from the artistic aspect, the sword is of higher quality. The better these components harmonize with each other, the better, more beautiful, artistic and of higher quality the blade is. To be able to judge this, it is important to see many good or only good blades. Bad art spoils the eyes.
Of course you have to be aware that swords of certain periods or different schools have different "beautifulnesses". An Ichimonji blade, for example, will have a different aesthetic effect than a Kotetsu blade in almost all criteria, and thus will show different qualities and different beauty. A picture by van Gogh, for example, differs in most aspects from a Rembrandt, but both these works have inherent beauty and artistic expression.
In order to understand such different beauty, it is absolutely necessary, when looking at a good blade, to acquire knowledge that can only be gained by studying the subject and training the eyes.
Japanese blades are not only an art, whose study and enjoyment brings a certain delight to the observer, but also an art for whose genuine understanding and appreciation the observer has to contribute something in the encounter, namely openness, knowledge and good eyes.
It is also necessary to learn the characteristics of the different schools, provinces and masters, so that the blades and consequently their smiths can be identified.
The typical form of the Japanese sword, in the vast majority slightly curved, single-edged and with a central ridge, has been developed over time and changed several times due to practical needs.
The main characteristics of the Japanese sword are:
All these characteristics are present in a good blade. They only become apparent and recognizable when they are made visible by a competent polisher in painstaking and patient manual work. The polisher needs to know how the blade was originally conceived, because the different styles of forging require different treatments. To be able to judge a sword correctly according to its qualities, the previously mentioned knowledge is important.
Polishing, the proper restoration of a blade is only possible if the polisher knows what he is polishing. Every age, every school and every style requires different sharpening and polishing methods, which are determined by the construction of the blade in order to preserve the specifics of the style.
Self-experiments on Japanese swords, by whatever means, are to be rejected, as such methods can ruin a blade.
A good polish is achieved by careful, time-consuming sharpening of the blade with a series of stones of varying texture and hardness, which can only be done by hand. This process reveals surface structures (kitae-hada) and the various radiant hardening effects on the blade. For example, if a blade has been hardened at a high temperature, the martensitic crystals - nie will appear as a small shiny diamonds, while a lower hardening temperature produces much smaller nioi crystals, which appear as milky mist or cloud patterns.
In order to study and appreciate the Japanese sword as a work of art, one should begin with the study of sword forms.
Than one should examine the crystalline structure of the tempering line, the quality of the steel and the forging pattern and last but not least one should consider the tang with the possible signature.
The tang also shows important features, such as the color of the rust, the file marks, the holes for the mekugi and, if present, of course the style and form of the inscription, which has to be observed.
All these criteria together can give clues as to the time when the blade was made and the identity of the artist or his students.
Throughout Japan's history, until the Meiji Restoration in 1868, swords were obviously used for combat. Therefore, samurai made great efforts to own a good sword, since it was the weapon they might have to fight with the very next day. Apart from that the sword together with its mount was always a status symbol.
How highly swords were valued may be illustrated by the following incident. The Shogun had an eye on the family heirloom of the daimyo of Tosa, a sword of Kanemitsu. The daimyo refused to give the sword to the Shogun with the statement: "Even if I had to give up all of Tosa for it, I would not surrender the sword to anyone... !"
Because of this episode, the sword got its name "Ikoku Kanemitsu" (ikoku = worth a province). Today this sword is classified as Juyo Bunkazai, i.e. an important national treasure.
Since it was extremely difficult to acquire a work of a famous swordsmith, many swords were already in old times decorated with false signatures. This was even done by the smiths, who later became famous for their own works. There are many forgeries for some smiths, such as Kotetsu, Shinkai but also others. From this fact one can conclude: since there are many Japanese swords which are either wrongly signed or whose quality is poor, it is extremely important to study swords intensively in order to distinguish good from bad blades and genuine from false signatures.
It is advisable to proceed as following when evaluating a blade.
Based on the form one attempts, at least approximately, to determine the period of time in which the sword was made.
Die nach der Form ermittelte Zeit versucht man durch Studium des Musters der Härtelinie zu bestätigen, wobei auch die Schule, zu der der Schwertschmied gehörte, evtl. festgelegt werden kann. Unter Umständen ist hier schon der Schmied der Klinge zu erkennen.
Through close inspection of the surface of the sword, one can finally determine in which period of time - Koto, Shinto or Shin-Shinto - the sword was made. Eventually one can also draw conclusions about the school or the master himself.
A close study of the boshi and the entire point can also provide further information about which master or school the sword actually comes from.
Afterwards one examines the tang for its specifics and reads the eventually existing signature. It is pleasing when the typical style of the master is already unmistakably recognizable in the blade itself. Ideally the signature of the tang should only be a confirmation of the recognized style and technique.
The earliest iron swords found in Japan were probably imported from Korea and China, but were soon also made by local blacksmiths. Almost all these swords are archaeological finds and were recovered from burial mounds scattered all over Japan.
These blades are all straight, single or double-edged. It should be noted that the single-edged ones have a kire-ba-zukuri form, while the double-edged ones are either also in kire-ba-zukuri form (implemented on both sides) or have a central ridge on one side.
These Jokoto swords were mainly used by foot soldiers as stabbing or thrusting weapons and were hardly ever used as cutting weapons by mounted warriors.
In the late 9th century, cavalry was increasingly getting importance in Japanese warfare. This kind of warfare created new quite different expectations for the blades. As an answer to those requirements, the swordsmiths developed curved blades. In the earliest blades of this type, the curvature towards the handle is more pronounced. This made these swords more suitable for the mounted fighter. Thus over the years the imported shape was changed, improved and finally the unique style that distinguishes the Japanese sword was developed.
After the 10th century slowly the fights of the Japanese against in the meantime strongly pushed back natives of Japan, the Ainu, subsided. About that time the different Japanese families had began to fight among themselves. This produced strong demand for the swords, which were suitable both for the fight between riders as well as for the fight between riders and foot soldiers.
The swords developed for this purpose are about 80 cm long (measured from the tip to the beginning of the tang) and have a deep curvature in the part of the blade close to the tang, while the curvature towards the tip almost completely disappears, making the sword suitable for thrusting. The tips are very small in this period. The prevailing hamon of this time was a suguha in its various forms.
This blade shape is called tachi. They were worn hanging on the belt with the cutting edge down. There were also tanto (daggers) at this time, but only very few of them are still preserved today.
The establishment of the new military power centre in Kamakura by the Minamoto clan marked the end of the high Heian culture of the Fujiwara family. Power and sobriety, influenced by ascetic Zen Buddhism, now became the ideal of the warrior nobility.
Although the swords still had the lowest point of curvature near the hilt, they became wider towards the tip compared to the blades of the previous epoch. The point itself became longer and stronger, chu-kissaki and ikubi-kissaki became predominant.
The pattern of the hamon also changed many times. Besides a calm suguha, choji-midare pattern of flamboyant motion and beauty has emerged.
Many tanto from this period are now preserved. These daggers are approx. 24 cm long and their back is either strait or has a slight tilt towards the cutting edge.
In the years 1274 and 1281 the Mongols tried twice to conquer Japan. However, they were stopped by the desperate will to fight of the Japanese. In both cases, a typhoon destroyed the Mongol fleet, which was called kami-kaze, "divine wind". As a result, the Japanese warriors were able to defeat the surviving invaders relatively quickly.
On this occasion the Japanese were confronted with completely new tactics and weapons. For example, the Mongols had wadded leather armour, which could hardly be penetrated with the Japanese swords of the time. In the battles which were fought after the Mongol invasions, it is already apparent that the Japanese had learned from these battles. Instead of mounted individual warriors, they now increasingly relied on foot troops in a fixed battle order with massive support from archers. The heavy armour (o-yoroi) was more and more replaced by the lighter do-maru. This more practical type of armour was from now on worn not only by foot troops but also by high-ranking warriors.
The tachi from this period do not have such a deep curvature anymore and the curvature itself moves more towards the middle of the blade (tori-zori). The blades are getting wider and thinner in the back, the cutting sides are no longer as convex (hira-niku) and the tips are becoming longer.
There are still many daggers from this time. These tanto are slightly longer than the earlier ones and in most cases have no curvature whatsoever (mu-zori).
This period was characterized by the establishment of two imperial courts in Nara and Kyoto, which fought for 60 years over supremacy. In the end, the northern court in Kyoto was victorious owing to the support of Shogun Ashikaga Takauji.
The battles of that time took place mainly in the mountainous area between Nara and Kyoto, which meant that larger cavalry warfare was relatively uncommon due to the unfavourable terrain. The fighting commonly took place between troops of foot soldiers armed with tachi and naginata. To reduce the weight of the long tachi, the casane, the width of the blade's back, was kept relatively thin. The mihaba was widened. In addition, bo-hi in all variations can often be found, which brought additional weight reduction.
The armour of this time (do-maru and haramaki), were lighter than before to guarantee the mobility of the foot soldier. The large armour (o-yoroi) went out of fashion due to its heavy weight.
The daggers of this period were even longer and wider, than from the earlier periods. It is worth mentioning that from this time on there are also curved tanto. These are longer than the daggers of the previous periods and their casane is relatively thin.
These tanto can even be longer than a shaku (30.3 cm), which means that these daggers are technically should be called wakizashi. This is the time of the "invention" of the short sword. Although in the earlier periods there were blades longer than one and shorter than two shaku, these blades were so called ko-dachi. They were also worn like a tachi. This is why they have to be considered a different type of sword than the wakizashi.
The tachi blades of this period differ from the form of the earlier swords. The blades lose the extreme width (mihaba), as well as their extremely long tips. Also their overall length becomes shorter.
Significant is also, that the centre of curvature moves upwards, i.e. towards the tip. The "invention" of the katana is of essential importance for this period.
The way the swords were carried has also changed. Long tachi hanging with the edge down was worn less and less. The warriors rather prefer to slip a now significantly shorter katana edge up into the belt. This new way made it much easier to draw out the blade. This technique proved its worth in the increasingly frequent fights of the foot soldiers. A medium standard length for swords of this time is therefore approx. between 65 and 70 cm.
Also the wakizashi became more popular. It was produced in hira- as well as in shinogi-zukuri and enjoyed increasing popularity as an "auxiliary sword".
The daggers of this period are again somewhat shorter than in the previous period with approx. 27 cm and resembled in style the daggers from the late Kamakura period.
This period is determined by the constant struggles of the various warlords and their parties across the country and almost complete collapse of the central power.
Battles were fought by contingents of troops in a fixed battle order. Knightly individual battles as in earlier centuries no longer occurred. As main weapons of this period were used lances and matchlock muskets of Portuguese design. Swords were only needed in the toughest close combat. The blades, which were mass produced from inferior steel at that time, can nowadays only be described as weapons and can hardly meet the requirements of a work of art. Beside the many poor mass productions, of course, as always, some high-quality blades were forged, which satisfy the expectations of a work of art.
Two types of katana originate from this period, the uchi-gatana with a short tang, for use with one hand with a length of approx. 64 cm, and a katana approx. 75 cm long with a rather longer tang for two-handed use.
Wakizashi were slightly longer than in the previous period with a length of about 50 cm to 55 cm and were worn together with the katana. The wearing of two swords became a fashion, which later developed to have both swords mounted identically. The practice was than formalized and regulated by government, coining the term "dai-sho" (lit. big-small).
Tanto from this time appear to be of four types.
Small daggers in hira-zukuri without sori or with reverse sori. Slightly wider and longer daggers with saki-sori. There are small daggers whose blades and tips are almost straight and not to forget double-edged daggers (moroha-zukuri).
With the beginning of the Keicho era (1596) the Koto period ends. In the following decades, the sword forms change and the shinto sword is emerging. These shinto (lit. new) swords have quite distinct appearance, depending on the particular era, they are created in. At first, during the Keicho era, blades similar in shape to those of the shortened Namboku-cho period swords were forged. The typical blade of the time has a slight curvature and does not become much narrower towards the tip. The casane becomes thicker again.
Swordsmiths did not produce their own steel during this period, but sourced it from professional manufacturers. Imported steel or iron were also used. These different qualities of steel also allowed or rather demanded other forging methods. This has resulted in the change of the hada and the hamon - which is why a Shinto sword has a different aesthetic effect than a Koto blade. The famous masters of the Shinto period still forged artistically outstanding works.
The swords of this period are no longer used in battles. The only use they find are the duels. This creates new demands on the sword. It was no longer required to penetrate an iron or leather armour, but just a cotton or silk kimono. The taste in artistic terms has also changed and new variations of the hamon had been developed.
Design or forms according to the principles of the Gokaden, the five traditional schools, are rarely seen in the new swords. The relative freedom of movement and lasting peace made it possible for the smiths to travel. They also were often sent by their princes to study art and craft from the masters in other provinces. These traveling smiths were absorbing and collecting new influences and techniques, and through this mixing previously distinctly different regional styles in something new, not existing before. Many master smiths were creating many different styles. From this time on, one can only barely speak of the five old schools. New emerging schools are now named after their founders or a city, where they were located.
Tanto are produced less frequently. The majority of the tanto and wakizashi are resembling those of the Namboku-cho period in length, width and form, with the exception, that the casane is now thicker than it was in the original.
Due to the peace in the Tokugawa period, bushido, the "way of the warrior", became dominant for the class of the samurai. Fencing schools were established and new forms of sword fencing were developed, in which one no longer practiced primarily cutting techniques, but also the thrusting with a blade.
Accordingly, in the Kanbun period the sword became straighter with a shorter tip. The form of these blades was called kanbun-sugata.
After 1652, the samurai had to carry two swords, the dai-sho or the pair of swords.
Daggers were rarely made after this date. However, when tanto were forged during this period, models for their shape were taken from of the Kamakura period.
Around 1688, the economy and trade flourished. The very luxurious Genroku culture dawned. Rich merchants, who were only allowed to wear a wakizashi, had short swords made by the most famous swordsmiths. There are some outstanding masterpieces from this time.
With the end of the 18th century, Japan experienced a wave of revival to the traditional values, from which also swordsmiths were not unaffected. As a result, copies from all periods were produced, but they were somewhat wider and again somewhat longer.
Copies from the Namboku-cho and late Kamakura periods were very popular. Old forging methods were rediscovered and reapplied, so that blades with very long tips and extreme hada can be seen from this period. This also applies to the tanto of this late period.
The year 1876 can only be regarded as a rather bleak year for the art of swordsmithing. In this year, the edict of Emperor Meji banned the wearing of swords in public.
The need for blades thus dropped to zero. Swordsmiths now made their living by making household items and tools for agricultural use or by producing cheap blades and other metal goods for export. Nonetheless, it is to be owed to Emperor Meji that the art of swordsmithing was not completely lost, as he supported blacksmiths by retaining them at the Imperial Court or through commissions.
The many shin-gunto swords, made by thousands from industrial steel for the military, are from an artistic point of view insignificant and worthless. One way or another they are belong to the to the realm of the militaria. No need to pity these blades, when they were confiscated and destroyed by the allied occupation forces after 1945.
After the Second World War the blacksmiths Miyairi Shohei and Takahashi Sadatsugu, honoured as "living national treasures", have continued the tradition of making not weapons but works of art in the form of weapons. In this tradition they were followed by the blacksmiths Gassan Sadakatsu and Sumitani Masamine.
Since 1955, the Committee of Cultural Assets Conservation has been nominating "Ningen Kokuho", i.e. "living national treasures", among them creative artists from some other disciplines, such as ceramics and textiles, but importantly also metalworking artists.
The tradition of sword-making is continued to this day and, like the study of blade polishing for the preservation of ancient cultural techniques, is supported by the Bunka-cho, the Ministry of Culture, and also by the NBTHK. That is why today there are again good and excellent smiths and polishers able to restore the old beauty of the blades.
A perhaps somewhat provocative title for a résumé, an outlook and yet at the same time an important advice.
As already mentioned, it is quite possible to deduce the time, the school and the smith from the characteristics of a sword by analysing style and form as described above. For this, of course, the knowledge of many representative masterpieces is quite valuable and helpful. When identifying a blade, however, one should not forget that there can always and everywhere be exceptions to the above rules.
It is therefore essential to study the classifications and the special vocabulary of sword terminology in depth and to be familiar with them.
It is of little use to look at many "blank weapons" of Japanese provenance if they are of poor quality and in inadequate condition. Only good blades of high quality and artistic value will help in serious study.
If you are really interested in the art form of Japanese blades and kodogu, there are only two ways to train your knowledge and your eyes: First, by looking at good swords and their mounts and second, by an intensive study of specialized literature.