[From January Issue 2014]
There’s a paper called “Tenguchoushi” that’s so thin that if you put it on your palm, you can see the creases in your skin beneath. If you place it over a newspaper, you can easily read the articles underneath. Tenguchoushi is currently thought to be the world’s thinnest paper. One square meter weighs 1.8 grams. A sheet the size of half a tatami mat is lighter than two one yen coins.
A company called Hidaka Washi Co., Ltd. (President CHINZEI Mariko) in Hidaka Village, Takaoka County, Kochi Prefecture, developed this paper. The “washi” that constitutes part of the company name, is paper made from natural ingredients to a traditional Japanese method. The company used to make each sheet by hand, but began using machines in response to demand for rolls.
It is said that Tenguchoushi originated from “usu-mino” manufactured in Mino (today’s Gifu Prefecture) in the 17th century. From the middle of the Meiji era (19-20 century) Kochi Prefecture began production of it in earnest. Exported in large quantities to the West, it was used mainly as typewriting paper, wrapping paper and for coffee filters. In those days Tenguchoushi wasn’t as thin as it is today.
Since the company was established (in 1949), it has specialized in making thin paper. In order for the quality of its paper to be better known, the company has made it available for use in the restoration of so-called cultural assets: old paintings and documents. To repair a heavily damaged document, it is sandwiched between thin sheets of washi. As Tenguchoushi is robust despite being so thin, the company was asked to make it even thinner.
Tenguchoushi’s reputation for being thin and durable immediately spread to museums, art galleries and libraries around the world. The lack of fine paper suitable for the restoration of damaged cultural assets and old documents had been an issue in other countries, too. The company not only supplies paper, but also provides explanations, using examples, of the proper use of washi. “Apart from Africa, Tenguchoushi is now used on all continents,” says senior managing director, CHINZEI Hiroyoshi.
Shedding light on the company’s effectiveness, Chinzei says, “Without chemicals, using only natural fibers, we manufacture ultra-fine paper. We also specialize in matching the color of our paper to that of the item being restored, a service other companies can’t provide. Tenguchoushi is too thin to be dyed afterwards. So we dye the fibers used as raw materials to match the color of old documents and suchlike.”
“The hardest part is making delicate adjustments to the quantity of ingredients and water used, and to the speed of the machinery, in order to achieve the optimal paper thickness to make a satisfactory product,” says Chinzei. “However, if we only consider our own convenience as manufacturers, we may become complacent. To prevent that from happening, we’d like to further improve our technology by taking challenging orders from customers.”
Text: ITO Koichi