OceanoNox

I'd like to see a document that describes that very special method that us stupid gaijin don't know about. I did not see anything like that in several old books (鐔に見る日本の意匠, 鐔芸術考, 鐔入門 : 百人百鐔, or even 人倫訓蒙図彙). I don't recall it being mentioned in Western publications either. So, something that Japanese and non-Japanese experts don't know about... But we do know that charcoal and urushi were, and still are, baked onto the surface of iron items. But what do I know, I am a stupid gaijin.

Easiest and fastest is X-Ray Fluorescence, but it will only get the patina composition. But this is already a big thing, because the recipes for patina should vary according to various places.

Is the mimi uchikaeshi? If so, I am amazed at the skill required to make it look so good. Very nice!

Thank you Manuel and Jean for the information. It was really helpful.

So that is why umegane sometimes look like they curve a bit towards the hitsu ana on their periphery! By inlet, did you mean that the ends of the nakago ana are expanded to insert the sekigane, or that the wall of the nakago ana had a small groove inside? Thank you for the answer.

I have been looking into sekigane and umegane in general recently. Sekigane because the iai swords I have usually don't have any (and antiques sold for iai do not either), and umegane because I think they are a very interesting way of using the hitsu ana when there is no kogai or kozuka. However, I cannot find much information (yet) on how they are made. I recall, when our dear departed Ford had a picasa page, that he said the sekigane held simply by friction. I understood it as meaning one would hammer it in place, and cut it to fit the nakago. The roughness of sekigane in general seems to confirm this assumption. I assume it is the same for umegane, but the finish is quite much cleaner for umegane in general. Do you know if there is a specific method to adding umegane? Is it simply hammered in place, and then polished and engraved? Could there be grooves carved in the wall of the hitsu ana to help secure them? Or would they be melted in cast in the hole?

Just taking a quick peak at the Owari section, and it's quite the leap from the original Japanese. I cannot understand how they got from 上下張り気味 (tends to be stretched up-down/vertically) to "squared seppa-dai". Likewise, going from 精良 to "hard and refined" (it seems to simply mean "excellent", which could be translated as refined, i.e. that forging took place to make the iron cleaner, but it does not imply hardness at all; 精 can mean strength, but more in the sense of vigor, it is incidentally one of the kanji for semen, to show the meaning of "vigor").

I don't know if this would work, but for starters, an evaluation of several dimensions for all extant tsuba would be a start. When I used the measurements from books and online collections, several times, only thickness or diameter were indicated. Proposed measurements: ➀ Easy and non-destructive: Thickness at the rim, thickness of seppadai, height/width of the tsuba, height and base width of the nakago ana, weight, shape of mimi. → This can be done readily by everyone, hopefully without scratching anything. ➁ Not so easy, but non-destructive (hopefully): Design trends (motifs, overal area cut out): possible use of AI for image analysis and treatment, Neutron diffraction (chemical analysis of iron, evaluation of forging), X-ray (chemical analysis of patina). → AI network for image analysis is being done currently. However, I have no idea how one would implement the analysis of designs. The measurement of total tsuba area and sukashi area seems straightforward, provided clear contrasting photos are used. I have personally done measurements of areas covered by specific features over total observed area, and it can show nice trends, but it is very very time consuming. → Neutron diffraction and X-ray analysis (XRF) were done by Barzagli and Kawami respectively. The XRF one is relatively easy because the tool can be rented (it's like a big hair dryer that one points at the item), but neutron diffraction is very difficult simply because one needs access to one of the few research centers that have it, and it means getting the tsuba there (as far as I understood, it's possible here in Japan to get neutron diffraction done for relatively cheap if the results are published in an open access journal. However, there is always the issue of handling at the facility and taking out the item from wherever they are stored/displayed). ③ Destructive: Hardness (micro Vickers is considered non destructive in the industry, but for antiques...). → Quite easy, although to get reliable data, a minimum of polish is typically required. Mr. Nakamura has shown such data in 1963 for several dozen iron tsuba, showing some scatter in hardness (hinting at either some forging or the combination of various irons and steels). A specific workshop or artist is unlikely to limit themselves to specific dimensions and materials. But if there are specific traits for various schools (presence of tekkotsu, prevalence of specific designs), the establishment of this kind of database could help narrow down possible origins of tsuba. With previous comments on papers being more liberally given in recent years, I do wonder whether the financial incentive to "mistakenly" attribute tsuba to famous craftsmen can be overcome. Certainly, it is possible that with this kind of inflation of paperwork, less stock will be put into those certificates, and a new system might be adopted.

I have seen the words 板鍔 (I assume meaning a plain plate) and 錬皮鍔 used for older periods. The leather one is usually soaked, hammered, dried, and lacquered, and then reinforced with a metal rim and large seppa (or so I understand). Mr. Ogawasara in his book 鍔 wrote that the simple and naive designs on tosho/kachushi tsuba are an evolution of the plain plate tsuba worn by lower ranking warriors (Mr. Katsuya calls it the development of "folk art"). And there was also some development from the richly decorated tachi tsuba worn by more wealthy warriors as they started to wear uchigatana.

To give more precision, the terms 陰透かし (or 影) and 陽透かし are also used: the former means the design is cut out of the plate (most of the plate remains), and the latter is removing the metal around the design (only the design and whatever metal is needed for structure remain).

I think (based on what the tsuba I have seen as labelled ko-tosho or ko-kachushi) Bokuden meant 影透かし (the design is cut away, the metal around it remains).

The earliest mention of tsuba with sukashi (cut out, called 切り抜き) I know of, is Tsukahara Bokuden (1489 – 1571). In his 百首, he wrote that one should prefer a tsuba with cut outs, instead of plain thick tsuba (鍔はたゞ切り抜きあるを好べし; 厚く無紋を深く嫌へり). He also mentioned that one should prefer thin/old tsuba to new/thick tsuba (新鍔は如何に厚くと切れぬべし; たとえ薄しと古き好めり). No one knows how old he meant, however. We could suppose that tsuba with cut outs were considered not new by his period (and that would still match with the above statement that sukashi only appeared after 1402).

Thanks @GRC, I look forward to reading new stuff. The age of tsuba interests me particularly because I want to study the evolution over time. Oh, how I wish there were records to be found.

I simply quoted the description of the book. Unfortunately, as you pointed out about the rust in sukashi tsuba, experts make mistakes (innocent or not). But to make it clear, I have no pre-existing belief in terms of tsuba. As it is, I trust other scholars and enlightened amateurs. Out of curiosity, can you link or give info about the Ashikaga castle and the findings in its remains?

I took this as meaning that Otomo Sourin showed one item he bought for 4500 ducats, and that item was an iron tsuba ("not even gold"). But your interpretation makes more sense now that I look at it more closely.