Spotting Fakes — An Introduction to Authenticating Japanese Swords

The Existence of Fakes―The Greatest Risk Collectors Face

Unfortunately, counterfeits exist in the world of Japanese swords. While the sword market has a history of development spanning over a hundred years, the history of forgeries has accumulated alongside it. Forgeries take many forms: gimei created by falsely engraving the signatures of master craftsmen, ato-mei where signatures are added to originally unsigned blades, and awase-mei where blades and tangs from different periods are joined together to appear as one piece.

Especially for works by renowned sword craftsmen and masterpieces designated as Important Japanese Swords, the motivation to create sophisticated counterfeits is strong due to the high valuations expected. In a market where transactions in the millions to tens of millions of yen are not uncommon, determining authenticity literally affects a collector's assets. Possessing foundational knowledge of authenticity appraisal is an indispensable defense mechanism for modern collectors.

Gimei―The Most Widely Circulated Forgeries

Gimei are signatures of renowned sword craftsmen engraved onto blades at a later time. This is the most common form of forgery seen in the Japanese sword market, with a history of continuous practice since the Edo period. Because swords bearing the signatures of renowned craftsmen see dramatically increased market value, the temptation to add signatures regardless of blade quality to inflate value always exists.

To distinguish sophisticated gimei, it is necessary to observe not only the script style and character form of the signature, but also the type of file marks (yasuri-me) on the nakago and their fine details, as well as the position, depth, and balance of the signature in a comprehensive manner. Additionally, it is essential to confirm that the period of activity of the sword craftsman recorded in the signature matches the techniques and form of the blade. If a Kamakura period craftsman's signature is engraved on an Edo period blade, the mismatch in techniques and period becomes an obvious contradiction.

Ato-mei―Inserting Signatures into Unsigned Blades

Ato-mei are signatures engraved onto blades that were originally unsigned by someone in a later period. The reality that signed blades have higher market value than unsigned ones is the fundamental motivation behind this alteration.

The most typical way to identify ato-mei is the unnatural appearance and condition of the nakago. Normally, the nakago develops a deep rust color called ko-sabi from contact with air over several hundred years. When ato-mei is present, the newly engraved signature area often shows a distinctly different color tone from the surrounding ko-sabi. However, sophisticated forgers hide this inconsistency by artificially tinting the entire nakago or mimicking rust through acid treatment. Distinguishing such alterations requires observation under multi-directional lighting and expert appraisal skills.

Large-Scale Remounting Unsigned Blades and Combined Signatures

Large-scale remounting unsigned blades are swords where the original signature was lost as a result of extensive remounting of the nakago. This is not strictly a forgery, but the lack of a signature makes identifying the sword craftsman difficult. This is often seen when tachi blades were shortened for use as uchigatana.

Awase-mei are formed by joining a blade and nakago that are originally separate things as if they were a single sword. This is more difficult to distinguish than gimei, and requires comprehensive judgment of whether multiple elements—the period feel of the nakago and blade, the nature of the steel, and the degree of wear—are consistent with each other.

Practical Checklist to Confirm Before Purchase

Even when leaving the determination of authenticity to experts, there are practical points that purchasers should confirm at minimum. The following are checklist items that can be used in actual transaction scenarios.

• Verify the issuing institution and date of the appraisal certificate, and cross-check that the recorded content (craftsman name, period, shape) matches the characteristics of the actual piece.
• Request photographs of the nakago from multiple angles and under multiple lighting conditions, and verify that there are no unnatural differences in the file marks or rust coloration.
• If there are accompanying box inscriptions, scabbard inscriptions, or documentation regarding provenance, verify the consistency of the content.
• Consult with the seller about whether you can directly examine the actual piece before purchase, or whether a viewing by a trusted third party is possible.
• Confirm in writing beforehand the seller's policies regarding returns and refunds.

Failing to perform these confirmations is the most realistic way to avoid troubles regarding authenticity later.

Quick Reference Table of Forgery Types and Identification Methods

The types of forgeries discussed so far can be organized as follows.

This table is merely a guideline for grasping the overall picture, and expert appraisal skills are essential for actual determination.

Four Perspectives for Distinguishing Authenticity

Four basic perspectives for determining authenticity are as follows. First, verify that the jihada and hamon technically match the period and school of the craftsman recorded in the signature. Second, verify that the rust color of the nakago is ko-sabi, exhibiting natural aging over several hundred years. Third, examine in detail whether the type and expression of the file marks engraved on the nakago match the styles unique to that craftsman. Fourth, confirm that the overall shape, thickness, curvature, and width of the entire sword possess a natural beauty appropriate to its period. Only by comprehensively verifying these four perspectives can one approach a judgment of authenticity.

The Certainty and Peace of Mind Protected by NBTHK Appraisal Certificates

Self-directed authenticity appraisal is extremely dangerous, even for experienced collectors. Even professional appraisers well-versed in Japanese swords may find it difficult to completely distinguish sophisticated counterfeits. Therefore, purchasing only swords with appraisal certificates from the Japan Art Sword Preservation Society (NBTHK) is the most reliable defense strategy available to collectors. NBTHK appraisals are issued after examination by a consensus committee of multiple experts and are globally recognized as the highest authority in current Japanese sword appraisal.

NBTHK appraisal certificates are ranked in four levels: preserved sword, specially preserved sword, important sword, and specially important sword. Higher-level appraisals undergo stricter examination and command higher market value. It is also important to cross-check the content of the appraisal certificate (including craftsman name, period, shape, etc.) with the actual sword before purchase to confirm they match. Ultimately, purchasing from a trusted Japanese sword specialist is the greatest defense strategy available.

Choosing a Trustworthy Seller

It is no exaggeration to say that distinguishing authenticity ultimately comes down to selecting a seller. Stores with a track record of specializing in sword transactions over many years and specialists who primarily handle swords with NBTHK appraisal certificates significantly reduce the risk of handling counterfeits. When considering a purchase, the store's track record, the thoroughness of their explanations, and their responsiveness to questions are also important factors in making a judgment.

Furthermore, if you have any questions, it is important to ask the seller freely before purchase and request explanations until you are satisfied. Engaging with a trustworthy seller while equipped with knowledge about authenticity is the most reliable way to enjoy Japanese sword collecting safely for the long term.