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Collage on mulberry paper; MFA# 1999.706


Kozo/Paper Mulberry
MFA# 2002.145

Kozo is used as a general term for Japanese paper made from the inner bark of mulberry trees, such as the Mulberry paper Broussonetia papyrifera and bast paper fibers harvested from that plant. Kozo papers are often used for backing when Asian scrolls are relined. Kozo is an important paper fiber in traditional Japanese, Korean, and Chinese hand-papermaking. The inner bark requires little chemical intervention to create high quality, long fibers that are low in lignin. The long fiber length and high percentage of Alpha cellulose impart strength to Kozo papers.

Synonyms and Related Terms

kozo paper; paper mulberry; torinoko (at least 20% kozo); hosho (thick); moriki (delicate)

Physical and Chemical Properties

Paper fiber type: non-woody/bast. Using transmitted light microscopy, fibers appear thick walled with varying width. A distinct cuticle layer is present on the outside of fibers. Dislocations and cross-markings are present, but faint. Appearance with Graff "C" stain: purple-red, ranging from light to dark. Average dimensions of fibers: length 10mm, width 30 μm. Common pulping method: prepared by retting and mechanical separation.

Additional Images

Resources and Citations

  • Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
  • Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989
  • The Dictionary of Paper, American Paper Institute, New York, Fourth Edition, 1980
  • Marja-Sisko Ilvessalo-Pfäffli. Fiber Atlas: Identification of Papermaking Fibers (Springer Series in Wood Science). Springer, 1995.
  • Walter Rantanen. "Fiber ID Course." Integrated Paper Services. June 2013. Lecture.
  • Bernard Toale, The Art of Papermaking, Davis Publications, Portland OR, 1983