Tosa is an old name for Kochi prefecture in Shikoku. Tosa Washi has been produced since long ago in Heian period (794-1185) especially along the Niyodo river where is known as a place with clear water for good quality raw material, such as paper mulberry, for Japanese paper. Tosa is even appeared in “Engi-Shiki”, a set of ancient Japanese governmental regulations written in more than 1000 years ago, as a nation of paper production.
The charms of Tosa Washi is its variation which exceeds 300 types. Especially, very thin type called “Tosa Tengujoushi” is famous as the world thinnest paper with the thickness of about 0.03 mm.
The colors are varied, too. In a folklore from Edo period (1603-1867), one traveler named Shinnojo taught the production method for seven-colored paper to a samurai Aki Saburozaemon when Shinnojo was rescued from disease by Sabrozaemon. The seven-colored paper became very famous and was presented to Tokugawa shogunate. The folklore says, in the end Shinnojo was killed by Sabrozaemon who tried not to let other domain artisans learn the technique.
After Tosa Washi was presented to Tokugawa shogunate, the technique and production developed further during Edo period, and it became the largest production center in Japan in the middle of Meiji period (1868-1912).
Current Tosa Washi has pale, calm, and nuanced color variation despite such legend. The raw material used other than paper mulberry are Oriental paper-bush, Diplomorpha sikokiana, hemp, bamboo, and straw. After washing them well and boiling them, artisans whiten and wash them again. Then the material plants are beaten to be broken, the fiber is solved in a water with sunset hibiscus for viscosity.
Paper making method is largely divided into two ways; “Nagashi suki”, scooping fiber using a “Sukigeta”, a framed perforated-like tool and remove additional water, and repeating the procedure for some times. “Tame suki”, scooping fiber using bamboo screen-like tool called “Su”, and collate the thickness by shaking it right and left. Then placing thin clothe called “Sha” and put weight on it to remove water.
The resulted Japanese paper is hard (uneasy to be torn), light, warm (good humidity maintenance), good at water absorption (good quality for calligraphy), easy to be colored, and have good permeability. The qualities are very suitable for covering books and notebooks, interior goods such as shoji and byobu, small goods such as paper lantern, Japanese round fan, and umbrella, and for arts like hanging scroll.
Tosa Washi was designated as Traditional Craft by METI (Ministry of Economy, Trade and Industry) in 1976.