Identifying Plants Used to Make Japanese Paper

Although all Japanese papers are made from plants each different plant gives a different type of paper. Let’s look at the different types of fibers to see where these differences come from.

First, watch the video to see Dr. Shiroto analyze a printed book from the second half of the 17th century.

Paper Fiber Analysis

Plants used to make Japanese paper belong to the Dicotyledon group. The cellulose cells in a Dicotyledon plant all look alike, so if we enlarge them we can tell with reasonable accuracy what plant they are from.

Identifying the Plant Tells Where Book is From

Identifying the plant used to make the paper allows us to tell where the book is from. For example, Chinese books made in China and Chinese-language books made in Japan not only are bound in completely different ways but also make use of different types of paper. The paper used in Chinese books is called “bamboo paper” (chikushi). Chikushi paper fibers come from the moso bamboo, a plant of the Monocotyledon group. Unlike Dicotyledons, the cells in Monocotyledons come in a variety of shapes. Because chikushi paper could not be produced in Japan, Japan-made books in Chinese were printed on kōzogami (choshi). So as far as Chinese-language books are concerned, even if the book comes without a cover or colophon (a statement at the back of a book stating the name of the publisher, the date of publication, etc.) by examining the fibers we can tell if it was made in China or in Japan.

Paper Restoration

Correctly identifying the raw material is also of crucial importance in book restoration. For best results, the same paper as the original should be used. So one should never try to identify the paper based simply on color and consistency. What may look to the eye as gampi paper, for instance, could be kōzogami treated with the “hammering” method (uchigami) or even mitsumata paper. Only by carefully analyzing the paper using modern tools can the source material be reliably identified.

So fiber analysis is equally important for book history and book conservation.

Books examined in this step:

• Houryakukanki, early Edo period
  Click to see the image and information
• Kasen kingyoku shō, Tenna 3 (1683)
  Click to see the image and information

For your reference

Below are the data for each plant in case you get an opportunity to do formal paper analysis.

Source material	Cell shape	Cell size
Ramie (choma)	Flat or cylindrical with a vertical crack. The cross section is either rectangular with acute angles or elliptical.	Length: 60～250㎜ Width：10～80µm
Paper mulberry (kōzo)	There are wide and narrow ones. They are ridged, have joints, and cross. The narrow ones have pointed ends, the wider ones rounded ends with an elliptical cross-section.	Length: 6～21㎜ Width: 10～30µm
Gampi	Either flat or cylindrical with rifling marks; have knots, and the ends are round.	Length: 3～5㎜ Width: 10～30µm
Mitsumata	Irregularly shaped with the central part twice as large as the rest; the ends are round and sometimes split.	Length: 3～5㎜ Width: 10～30µm
Moso bamboo (Monocotyledon)	Large number of fibrous cells not found in dicotyledons (stem cells, tissue cells etc.)	Length: 1.5～4.4㎜ Width: 6～27µm

^{These photos by Kazuyuki Enami, Ryukoku University.}

Other Tips in Identifying Plants in Paper

Ramie fiber

Ramie fibers are very long and most appear to be cut. Compared to other fibers they are wider and shaped like a ribbon. Paper made from them is very white but the surface is rough.

Kōzo fibers

Kōzo fibers are longer than gampi and mitsumata fibers. They give a very white paper.

Gampi fibers

Gampi fibers have characteristically round ends. The paper tends to be less white than the preceding two fibers.

Mitsumata fibers

The distinctive characteristic of Mitsumata fibers is that the center is larger than the ends. Like the gampi, mitsumata paper is less white.