The Polish

Prerequisites: The Quench — you need to know what’s inside the steel, because polishing is how it becomes visible. Feeds problems: knowing what you’re looking at, keeping the craft alive

Practitioner

Reset one assumption first: the polisher is not sharpening the sword. A blade fresh from the smith is shaped, hardened, and rough-ground — functionally it could be made to cut with an afternoon’s work. What it cannot do is be seen. All the structure created upstream — the hamon’s crystal boundary, the folded grain, the fine activities — is locked inside a uniformly scratched gray surface. The togishi’s actual product is information: a surface finished so precisely that structures a few crystals wide become visible to the naked eye. Sharpness falls out as a byproduct, and polishers describe their work as revealing what the smith put there — or exposing what he didn’t.

The craft runs in two phases. Foundation polishing (shitaji-togi) is geometry: working wet, bracing the blade against a post and stroking it along fixed coarse-to-medium stones, the polisher trues every line — the ridge dead straight, the surfaces properly curved with the right niku, the point’s facets crisp. Mistakes here are permanent sculpture: rounded ridgelines, lost meat, a reshaped point. Each successive stone (the classical ladder runs arato → binsui → kaisei → chū-nagura → koma-nagura → uchigumori) erases the previous stone’s scratches with finer ones. By the end the blade is smooth, its geometry final — and still mute.

Finish polishing (shiage-togi) is where the reveal happens, and the tooling changes character completely: from stones you stroke the blade along, to slivers you work with the thumb. Hazuya — uchigumori stone ground paper-thin, backed with lacquered paper — is rubbed in tiny strokes over the hardened zone, whitening the martensite and lifting the hamon into view. Jizuya, a different thin stone, works the body steel, darkening it and raising the grain contrast. Then nugui: an oil bearing ultra-fine iron-oxide particles, rubbed in to deepen the body’s color to blue-black. The optics of the finished surface are differential: hard and soft structures now scatter light differently, so the eye reads the metallurgy directly. Finally the point gets its own dedicated finish (narume), and the spine and ridge flats are burnished to a mirror with a steel rod — the contrast of mirror, mist, and grain that makes a polished nihontō look the way it does.

At the very end sits a real aesthetic decision. In sashikomi finish, the polisher stops at nugui and lets the hamon show exactly as the quench made it. In hadori (also called kesho, “makeup”) finish, the polisher additionally whitens a band along the hamon with hazuya, brightening and smoothing its apparent line. Hadori dominates contemporary high-end work — it flatters nie-rich blades and photographs beautifully — but it can also draw a prettier hamon than the steel earned, and connoisseurs grumble when makeup outruns metallurgy. When you compare blade photos, know which finish you’re looking at; the same blade reads differently under each.

Two economic facts complete the picture. Time and money: a full polish is 10–20 working days of a master’s time and is priced accordingly — often comparable to a good used car, and a meaningful fraction of a new blade’s total cost. Steel is the budget: every polish removes metal that never comes back. A blade polished too many times goes “tired” — the skin thins until core steel ghosts through, the hamon weakens toward the edge, the niku is gone. Old blades carry their polish history like tree rings, and the first rule of ownership follows directly: you never polish a blade yourself, and you don’t commission polish casually. Conservation thinking, not cleaning thinking.

Expert pointers

Live issues: the hadori-versus-sashikomi taste war, entangled with exhibition judging and photography. The stone supply: finish polishing depends on natural uchigumori from quarries near Kyoto whose best seams are exhausted; polishers hoard old stock and the field quietly worries about the day it runs out — synthetics so far don’t fully substitute at the finish stages. The profession’s shape: roughly ten years of apprenticeship, a Living-National-Treasure track parallel to the smiths’, and even fewer practitioners — polish capacity, not forging capacity, is arguably the craft’s tightest bottleneck. And conservation ethics: when is repolishing a centuries-old blade preservation, and when is it consumption?

Misconceptions

• “Polishing is sharpening.” Sharpening produces an edge; polishing produces legibility and geometry, of which an edge is a side effect. A kitchen-knife sharpener and a togishi share almost no technique past the first stone.
• “A polish restores a blade to new.” Each polish subtracts steel from a finite budget. A polish can rescue a neglected blade’s beauty, but the blade is strictly older and thinner afterward. “Tired” is irreversible.
• “Anyone careful can polish a sword with fine sandpaper and patience.” An amateur polish destroys the geometry (the part that takes a decade to learn), typically halves the blade’s market value, and can never be “redone over” — the steel spent on the mistake is gone. This is the single most expensive beginner error in the entire hobby.

Check yourself

1. Why does the hamon become visible at all? Explain the mechanism in terms of what’s physically different on either side of the line and what the finishing stones do about it.
2. A dealer shows you two photos of the same blade, one in sashikomi and one in heavy hadori. What could the hadori version be hiding, and which features would you insist on seeing in the sashikomi shot?
3. The foundation stones set geometry; the finish stones set legibility. Which class of error is worse for the blade’s long-term life, and why?
4. Museums sometimes display important blades in old, slightly dulled polish rather than commissioning a fresh one. Defend that choice with the concepts from this topic.

Apply it

A comparison exercise (~30 minutes): find two well-photographed blades in contrasting finish — search a dealer site or the NBTHK/museum collections for one explicitly noted as sashikomi and one obvious hadori (the whitened band along the hamon is the tell). Write ten lines: what each finish makes easy to see, hard to see, and impossible to verify from the photo alone. You are building the skeptical-viewing skill that Schools, Eras, and Kantei depends on — and if your capstone is a review of a sale listing or museum label, this exercise is its first draft.