Tosa paper & blades

Tosa — the old name for Kochi — is mountains and water and very little flat land. It could not grow rich on rice. What it had was timber, charcoal, fast rivers and the raw fibres that grow on steep ground, and both of its great crafts come directly from that inventory.

Tosa washi: paper you can see through

Paper has been made here for over a thousand years — Tosa washi appears in Heian-period records — and the reason is the water. Papermaking needs cold, clear, mineral-poor water, and the Niyodo and Shimanto rivers are among the cleanest in Japan.

The prefecture makes an extraordinary range, but its distinction is the extreme end: tengujō, a tissue so fine it is measured in grams per square metre in single digits. The thinnest grades run around 1.6 g/m² — thinner than most human hair is wide, and translucent to the point of near-invisibility.

Conservation departments at the British Museum, the Louvre and the Vatican use Tosa tengujō to repair manuscripts. It is strong enough to hold a page together and thin enough that you cannot see it has been done.

That is a genuinely startling fact about a rural Japanese prefecture: some of the world's most valuable documents are held together by paper made on the Niyodo river.

Tosa uchi-hamono: blades made for work

Forging here dates to the Kamakura period, and expanded sharply in the seventeenth century when the domain's forestry policy created enormous demand for axes, saws and billhooks. Unlike the sword-descended traditions of Sakai or Seki, Tosa blades were agricultural — made for people who used them all day, every day, in wet forest.

The defining characteristic is free forging: no fixed dies, no standard patterns. A Tosa smith forges to the customer's hand and job, which is why the tradition survived industrialisation — it was never making commodities. It became a nationally designated traditional craft in 1998.

What you buy today is usually a kitchen knife, and the ones to look at are the rough-finished kuro-uchi blades with the black forge scale left on the flat — cheaper, more durable, and completely unlike a polished city knife.

Buying either

Both turn up at the Sunday Market, which is the best possible way to buy them — direct from makers, with no shop margin, and with the maker willing to explain. Failing a Sunday, the Obiyamachi arcade has specialists, and the prefectural products hall near the castle carries both.