Ganpishi paper

Washi paper is made from the bast fibers of the gampi tree, which grows wild in the warm regions of Japan. Gampi is very difficult to cultivate, but because of its high-quality fibers, it has been used for papermaking since the Nara period. Hishi paper, which appears in the Shosoin documents and Engishiki, was made from gampi, as well as other species of the same Thymelaeaceae family, such as Koganpi, Tosaganpi, Miyamaganpi, Kiganpi, and Onishibari, and probably also from Mitsumata (called Sakikusa at the time). Hemp paper and kozo paper were made in ancient China and the Korean peninsula from long ago, but gampi paper in particular is a specialty of Japan, praised as the "king of paper." Torinoko paper and Shuzenji paper, which have been produced since the Middle Ages, are also from the same family and have gained fame overseas.

Gampi fibers are delicate, uniform, shiny, and highly viscous. Branches about 2 meters tall are cut and the outer bark is stripped raw to make black bark, which is then processed to make paper in the same way as for paper mulberry. The viscosity of Gampi fibers comes from the high hemicellulose content, and its chemical structure is very similar to the mucilage of Alabaster arborescens and Deutzia monadelpha used in neri. In addition, when making washi paper, it speeds up the beating of the fibers, helping to disperse them evenly in water, slowing down water leakage from the sieve, strengthening the intertwining, and is effective in producing strong paper with good texture. Its demulcent effect is also evident when mixed with other fibers such as paper mulberry. The opportunity to invent the unique Japanese nagashisuki method, which uses a plant-derived mucilage called "Neri," is thought to have come from the production of ganpi paper (hi paper). Ganpi paper is dense and does not bleed ink.

[Machida Masayuki]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

日本の暖地に自生するガンピ（雁皮）の靭皮(じんぴ)繊維を原料とする和紙。ガンピは栽培が非常にむずかしいが、繊維が良質なため奈良時代から製紙に利用されてきた。『正倉院文書』や『延喜式(えんぎしき)』にみられる斐紙(ひし)は、ガンピや同じジンチョウゲ科のコガンピ、トサガンピ、ミヤマガンピ、キガンピ、オニシバリなどのほか、おそらくミツマタ（当時はサキクサといった）も原料としていた。麻紙(まし)や楮紙(こうぞがみ)は、古代中国や朝鮮半島でも早くから漉(す)かれていたが、とくに雁皮紙は「紙の王」とたたえられる風格をもった日本の特産である。中世以降の鳥の子紙や修善寺紙(しゅぜんじがみ)も同系統で、海外においても名声を博している。

　ガンピの繊維は繊細で均整がとれており、光沢があって粘性に富む。草丈(くさたけ)約2メートルの枝条を刈り取り、外皮を生(なま)はぎにして黒皮とするが、これを処理して紙とするまでの工程はコウゾ（楮）の場合と同様である。ガンピ繊維の粘性は、ヘミセルロースの含有量の多さに基づき、その化学構造はネリに用いるトロロアオイやノリウツギの粘質物と酷似している。また和紙抄造の際、繊維の叩解(こうかい)を速めて水中での繊維の均一分散を助け、簀(す)からの水漏れを遅らせて絡み合いを強め、地合いのよい強靭(きょうじん)な紙をつくるのに効果がある。コウゾなどの他繊維に混合抄紙した場合でも、その粘滑作用を発揮する。植物性粘液のネリを利用する日本独特の流し漉き法が考案された契機は、雁皮紙（斐紙）の製造から得られたものと考えられている。雁皮紙は質が密で、インクでもにじまない。

［町田誠之］

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