Rivkin

Kao is a stylized signature used on Japanese documents from ancient times. It is an addition to the name and is signature as such, signifying the document is prepared in the presence and hand signed or entirely handwritten by the said person. For example, copies of government rescripts do not bear kao, the originals do. Generally, kao would be associated with upper ranks of beaurocracy or government-recognized heads of important institutions. The use of kao on metalwork is generally a late (i.e. 19th century) tradition: swordsmiths and tosogu makers were usually not tasked with writing high ranking documents. Which is also an issue btw since if you read some 15-17th century swordsmith documents you have no idea is it the original, or its a copy made 100 years later by someone trying to prove something - I encountered this issue quite a few times.

I would add my general experience that all "function"-based arguments are 19th-20th century attempts to reconstruct why things were the way they were in the 12th or 14th century. Attempts often made by people with zero understanding of metallurgy (and thus not realizing their "concerns" are either false or could have been addressed easily by other methods) but most importantly the arguments produced without comparison how similar problem was addressed elsewhere. This being said it does not negate the possibility that original thinking leading to appearance of such features was also faulty (i.e. "fashion-based") and driven by some concerns that are spurrious. Its common today, it was common 1000 years ago. If you compare a Japanese made chip you will notice quite a few things like extra operations to clean the non-essential byproducts of technological processes, purposeful asymmetric arrangements of elements, which are different from American made ones with the same functionality. The reason is that the real data is noisy and its easy to come up with a theoretical "concern" which might or might not be relevant but sounds scary enough one needs to take precautions against it. Because Chief Designers in Japan and the US are generally different people, you end up with a different culture of how electronics should look like. In combat its even worse since it does not happen very often, when it happens its usually in random, multi-factor environment and participants when asked immediately afterwords have no cohesive understanding of what in hell they just went through. Its scary, its noisy and you don't see much beyond a few feet in front of you. Unless a war tool is next to unusable even novadays it often takes 2-4 decent size wars to realize what works and what's not. Were the faint signatures on early Japanese swords such because otherwise nakago would break? Its doubtful because you look at continental development of the same sword form and the nakago is even thinner in the center. Is it possible some very influential Japanese swordsmith believed it to be a concern and influenced the tradition for hundreds of years to come? Yes. There are cultures where grooves are cut off-center and asymmetric on both sides because otherwise the blade will be "too thin". And obviously the rest of the world generally dislikes asymmetric blades.

There were early Yukihide, but unfortunately its not at all consistent with what is seen here: yasurime especially, but also the way the kanji are carved. I almost want to say its a Meiji period's signature - they did not stop making boy swords in Meiji but the signatures are sometimes a bit more simple between Meiji and Taisho, nijimei included.

The signature's strokes are deep with distinctive large triangular shape, the yasurime is of a relatively modern type. This looks shinshinto or later. Unfortunately, its not clear which of the period's Yukihide signed nijimei so which yukihide it is - is difficult to determine.

That's something considerably more rare. Most continental guards are Chinese crossguard type until 12-14th century when you can start finding the early "tsuba" form. There are however exceptions - this is 10th century continental tsuba. Its obviously considerably more narrow compared to 14th century examples and bears some limited similarity to Kofun examples. Of note here the iron habaki bears the same edge decor as the tsuba and was made by the same hand, that of a swordsmith. By comparison soft metal habaki and guards would likely be a specialized trade.

Don't know how far early one wants to go. I guess Kofun is weird copper-iron alloy, with the usual gilding, gold with a large content of tin and other elements.

One needs a naked sword shot directly from above to see sugata with minimal lens distortion, example of activity etc. It seems to be in modern polish, should not be too much a problem to roughly understand what it is. By itself bohi like this is not a strong-specific kantei feature unless someone wants to enlighten me.

Well, sugata is "classic" so it can be anything but signatures towards the back of nakago tend to be koto. The writing does not have shinto feeling to it, but its more forceful with well defined strokes compared to most earlier signatures... Most likely late Muromachi, for example Higo Harukuni or the likes. Decent koshirae, I like the tsuba, I sort of like the wrapping. Its a decent period piece, I don't think its great, but its fun and enjoyable.

I collect iron kozuka and kogai, they tend to be early, these guys are Muromachi, the "namban-ish" style is probably Momoyama.

This used to belong to Bob Hanes.

Does not look bad. I would have send it to be shown to Tanobe sensei and if he feels its good to have it polished and then submitted for papers. As is, I still feel there is some uncertainty.

Thank you for your input. While living there I purchased quite a few items which had torokusho from different swords - daito with torokusho to tanto, a lot of daito with mismatched nagasa, signed blade which was noted as mumei etc. etc.. Comes out when you submit for export and its not a match.

The basic rule is if you see kinzogan to major name but no modern papers, unless the blade is clearly out of the woods - it means there is an issue. It might be a major issue or it might be that the modern attribution is similar, but two notches below, since if its just one notch below it quite often can still be papered. The general accuracy is hard to estimate since anything grossly inaccurate will be considered fake, i.e. "the attribution is wrong so the kao must be fake". And unfortunately Honami Kochu's papers have been faked with extreme accuracy. Part of the reason he also did a lot of attributions. So the acknowledged cases are most limited to Juyo+ blades where a modern sayagaki for example says - yes, kinzogan to x, but its really y. You do see certain patterns where modern attributions clearly diverge from the best Honami standards. There are also Honami whose judgements per se were not up to the standards - Nishu, to the lesser extent Koson, many others. Why there are so many kinzogan without kao, who made those, is not a well researched subject for obvious reasons, i.e. if its not signed, how do we know who did it. Reasonable guess its many side branches of Honami family, but its also of note that engraving kao was considerably (one might even say ridiculously) more expensive work compared to a signature without kao. Its possible that issuing "kinzogan without kao" was a lower cost appraisal option with some later generations.

Yes. Most likely cause is seller having a drawer with a few dozen torokusho from which he takes one at random when he sells something. Since the export requires actual match between torokusho and the goods, when it comes out they don't, it needs to first get new torokusho and then resubmit. If it has higher papers there is an additional trouble potential - they can open an inquest to the province which issued the torokusho and ask it to resolve the mismatch... In case if its provincial bunkazai or something, so that the locals clearly state that they have no particular interest in the blade on their end.

Ok, probably the first photo there was some weird angle which made it look like nakago has a proper finish, this is as o-suriage as they come.

Maybe a bit better. It matters a lot if its a prime level smith or very old sword, otherwise plus-minus. Yes, mumei ubu can be made and attributed.

NBTHK generally does not put "suriage", "o-suriage" etc. on papers. It is probably written "mumei (Takada)" and the rest is seller's narrative.

Its either o-suriage since it has one hole (meaning the original nakago is fully gone) or its ubu. Not with the best nakago finish, maybe moved hamachi and refinished, but mostly ubu. Hamon ending wide is not a reliable indicator of suriage unless its a very old sword or a smith who forged always with hamon ending sharp at hamachi. Sugata might help understanding whether its ubu or not, size-wise it is quite possibly near-ubu since at the time very long blades were uncommon.

I would be interested in buying, however can't offer much - and in the interest of fairness will state publicly why. The signature is near gone and I can't say anything about it, except it does not have strong Tsunahiro (is it even Tsunahiro? my kanji understanding is lacking) characteristics. The sugata is not typical for Tsunahiro lineage, which generally worked within the space defined by 1350-1380 Soshu tanto as defined by Hasebe/Hiromitsu/Masahiro. This is not even Sagami shape per se. Its tired as evident in horimono losses. Out of polish with fingerprints. Such papers are interesting for historic reasons but unfortunately when someone sells a tanto with them few assume it was inherited this way, and many - its a gimei that has been failed by modern shinsa. However it is an interesting old tanto which would be fun to hold in hand and try to kantei what it is. Can it be real Tsunahiro? I personally doubt it, but maybe it is, an unusual one. On a personal note - I like it. There is something about it which is appealing.

Thank you very much! I don't think I see modern NBTHK papers being generous with the name Kanezane assigned to mumei swords. I found online a few NTHK examples, but otherwise it feels like Kaneyoshi, Kanekiyo, even Kanetoshi are the names of choice.

I think it illustrates the point how subjective the "knowledge" can be, especially in a short term. My father once wrote that the only "science" which relies heavily on deduction and formal proof is mathematics, and maybe because of that mathematics might not be a "science" per se - instead of generating knowledge it converts it between equivalent representations. Some of which are arguably more useful than others. Other fields remind me of famous economics paper by a conservative Nobel prize winner which demonstrated strong correlation between nation's debt and GDP growth... except the growth part was dominated by zero debt countries like Somalia. To this point, I would address the issue of "chikei" in a bit different manner. Why use yet another term related to a nie formation? The reason might be is that very high contrast hada with wide black lines can be formed in multiple ways. It can be that the steel has different amount of carbon (high tends to be dark grey) or slag (in polished steel aluminum oxide produces black and phosphorus - deep black color). It can be that its due to martensite formation with a specific size, which does create characteristic black lines, i.e. "chikei". Therefore Houju hada while also black-striped is not seen as per se an advantage since many believe it has considerable "slag content" (though it was never tested afaik), but while in some poor images Norishige might look similar, more often than not it considered a superior steel since the black colored lines are formed by chikei. Overall, chikei is a telltale sign of upper end work, often present in Soshu and some other schools. In a related manner, Inazuma when you just look at it, something "similar" can be produced by folding lines, but if it comes with nie concentration it becomes a sign of upper-upper grade Soshu work.

On the one hand: yes, show it to people and you can probably submit it for papers as is. I have some doubts its a proper Enju signature. Not nearly enough to call it gimei, but enough to scratch my head. Especially since there were other Kuniyoshi smiths (including as strange as it sounds non-meikan ones) and it needs to be investigated a bit more. Sugata-wise its either early Muromachi or mid-late Kamakura. In any case it looks like a solid piece. Seeing boshi in detail + maybe some work if hamon/hada are visible would be helpful.

That is a rare certificate from an early year! Unfortunately, its appraisal is not too trusted nowadays, however it does not come out as crazy. It is a Muromachi tanto; being mumei it can different attributions. I don't think Kanezane is a common attribution today - assuming it does have Yamato traits, maybe it will be attributed to Tegai Kane... (i.e. Kaneyoshi), with a thick kasane and sugata like this Tosa Yoshimitsu is a possibility. Unfortunately, the polish state is not great so its all guesses. Nevertheless out of polish, Muromachi Yamato or related ubu blade is a strong possibility. I can't see how large are condition issues re mounts, but definitely it is the mounts that will impact the valuation considerably. Its an honest late work.

If you can't see a hamon but you can somewhat see hada when looking at an angle its a bad sign. It was probably a magnificent sword but how much of it can be brought back by fresh polish is a big gamble. It can come out well, it can be that what it is right now is the best it will ever be.

Its a rare writing of Yasutsugu (康次) for Sagami lineage, so there is only one entry in Meikan which ends around Tembun (1500-1520)... I am a bit surprised how the blade looks like and don't quite recognize this kind of papers.