This is an Akasaka or Higo style tsuba with the plum branch and bird motif that was roughed out but never finished. Given the angles at which the hitsuana meet the seppa dai, I’d lean toward Higo, but that’s not really the point. As we’ll see below the blank was worked with a chisel.
Each chisel stroke is easily seen in this part of the rim.
The openwork is chiselled very close to the kebori layout lines defining the shape of the rim and plum branch. Handmade files couldn’t have been inexpensive, so it probably made sense to keep their use to a minimum. Each tooth of a file required a cut with a chisel, so it was probably about as much work to make one as to cut out a tsuba like this.
Given the roughness here it looks like the maker was working quickly and confidently. Opening this up with a jeweler’s type saw would be slow work and hand made blades would probably also have been expensive. I seem to recall reading that they came into use in the Edo period, but don’t remember the source. I’ll have to look for more information. String and abrasive techniques were around well before that, but that would have meant even slower going.
It’s possible that the tip (left) of the upper branch may be the reason the work stopped. The chisel stroke cuts over the centerline of the design. It seems like that could be closed back up without much trouble, but maybe that would be asking for headaches later in the process (or from the boss).
At the right side here there openwork has been refined beyond the rough chiselling. It looks like it may have been scraped down. Comments from metalworkers are welcomed.
It’s interesting that work that’s quite rough is next to spots that are almost finished instead of working everything uniformly from the rough state. The nakago ana, seppa dai and hitsuana were “cast in stone” early in the process.
There are some coarse-ish apparent file marks visible in the most finished section, but they aren’t showing well with either the macro setup or microscope. I wonder if the rim was going to be finished off with a circular cross section or left flat. Interesting choice to have refined the branch tip to that point while the rim is still rough.
I found an interesting video on a likely process for making early files. It’s not about Japanese technique, but from what I’ve seen the methods were probably similar (and the production values here are better).
His whole project on recreating the antikythera mechanism with period methods is well worth checking out. Amazing stuff.
Thanks to Fred G for the subject tsuba.