The Thinnest Paper in the World

Jul 14, 2025

「EP.54」土佐和紙

TOSA WASHI / TOSA TENGU JOSHI
Kochi Prefecture

「transcript」

While the exact origins are unclear, records of Tosa Washi date back over 1,000 years. Kochi’s pure and fast-flowing rivers made it ideal for producing strong, beautiful paper. All Tosa Washi is prized for its thinness and strength, but Tosa Tengu Joshi stands out as the thinnest washi in the world. Nicknamed "the wings of a mayfly," it's nearly transparent and incredibly durable.

The heart of Tosa Tengu Joshi is in preparing the mulberry fiber. It is boiled, then washed under sunlight to both remove all impurities and achieve its beautiful white color. This ensures uniform strength and protects the paper against insect damage. The fibers are then hammered to separate them and further refined.

Next comes nagashi-zuki, a technique where a bamboo screen is shaken in water to evenly weave the long fibers. Achieving consistent thinness requires immense skill, something craftsmen can only master after over a decade of work.

Tosa Tengu Joshi is prized around the world, especially in restoring precious artworks and documents. Its breathability and resilience make it the top choice for conservators and artists alike.

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