I am forming sheets of paper, using kozo pulp, at the Minnesota Center for Book Arts. July 2019. Thanks to Alexa Horochowski for shooting the video!
In July 2019 I did a workshop at the Minnesota Center for Book Arts on Nagashizuki, or Japanese Papermaking. Bridget O’Malley taught the class, and is a former student of Tim Barrett, author of a foundational book and technical guide on the subject. The most noticeable characteristic of Japanese-style (and also more broadly East and South Asian-style) paper is that it can be made to be very thin. A couple incorrect myths: 1) except in rare circumstances, this is not rice paper, and 2) Japanese paper does not have to be thin; you can make it as thick as you like. The first myth is a colonial layover, from Europeans who did not understand how the paper was made. And … for thicker paper, just imagine me doing this scooping and dipping process in the video over and over until the fibers have piled up.
What plant is used, then? There are three main ones—kozo, gampi, and mitsumata. Kozo tends to be the most common and available, while mitsumata is the rarest. The inner bark of each of these shrubs is harvested, cooked, cleaned, beaten, and then put in a vat with water.
But wait! That’s not just water in the vat. The real key to making thin paper is not the plant species selection alone. It is crucial to add a deflocculant to the water—a.k.a. formation aid, a.k.a. tororo-aoi, a.k.a. slime—so that the inner bark fibers remain in a dispersed or suspended state. The slime-water takes longer to sift through the bamboo strainer because it’s thicker than water (see video), but this means the fibers are already calmly and evenly falling onto the filter pad, which makes for thin and strong paper.