I met Judith Duff in 2008 during a wood firing at Kevin Crowe’s Tye River Pottery near Amherst, Virginia. I had the pleasure of working several kiln firing shifts with her, and as we got to know each other she talked about her experience as a maker and the times she had traveled, studied, and exhibited in Japan. She mentioned that she and her husband Royle were investigating traditional shino glazes using North Carolina feldspars and local clays. I had the opportunity to visit Duff again in 2009 at her studio outside of Brevard, North Carolina, and was able to see and touch the pots, and became truly fascinated with her research.
The Origins of Duff’s Quest
Duff has studied and traveled in Japan many times, visiting potters and learning the aesthetics, history, and technical information about traditional Shino clay bodies, glazes formulas, and firing. Duff said, “ During these trips I became especially intrigued with the traditional Japanese shinos that were so soft and beautiful, but in marked contrast with the shinos that I had worked with and knew about in America.”
On her second trip to Japan in 2000, Duff met Shozo Michikawa, a Seto potter who has become an important collaborator and good friend. Michikawa has visited Duff in the US several times, and he helped her build an anagama kiln at her studio.
In the spring of 2004, Duff made her fourth trip to Japan to work and exhibit in the Mino-Seto area. On that trip, Michikawa introduced Duff to Muryo Naito, a well-regarded Shino potter from Toyota City. He was instrumental in providing her with essential information about clays, feldspars, glazes, and the type of kiln and firing schedule she would need to go home and start her research. Naito graciously provided Duff with material samples to be analyzed and plans for the specialized kiln designed for firing traditional Shino glazes.
Analyzing Materials Research
Upon her return to the US, with a grant from the North Carolina Arts Council, she had the materials analyzed for chemical and mineral makeup and particle size, and she started testing clay bodies and gathering samples of local feldspars. At her studio she constructed a stamp mill to crush the feldspar and started building a gas-fired kiln constructed with floors, walls, and arch (all of which were 18 inches thick). This highly insulated kiln would be fired for 100 hours and cooled for seven days in order to melt the coarse feldspar and develop the traditional type of shino glazes that are so highly valued in Japan. Her analysis of the North Carolina feldspars confirmed that the soda feldspars (Zemex) from the Spruce Pine area were remarkably similar in composition to those in the Seto-Mino area of Japan. Duff created 3 clay bodies and 20 glazes to test. These coarse feldspathic glazes are hard to work with (like wet sand), so she had to develop new simplified forms to accommodate the glazes.
In the spring of 2005, Duff loaded 150 pots into the kiln and followed Naito’s firing schedule. The results of the firing were promising: of the 20 glazes tested, three were viable. One of the three clay bodies was superior to the others (Duff had Highwater Clays mix them up for her in quantity). The second firing was in September of 2005 and possibly was the best one of all. Responding to the results, Duff said, “I had several pieces that showed a lot of black, carbon-trap surface to contrast with the white.” Michikawa, who happened to be in Brevard at that time building Duff’s anagama kiln, was there for the unloading and was quite excited and pleased by the results. The range of results came from variables such as glaze thickness, variation in the particle size of the feldspar, and the reduction atmosphere in the kiln.
Mineralogy from XRD/XRF* (results in percentages)
Brentwood XRF Chemistry (results in percentages)
Mineral Lab Mineralogy-Shino Clay (results in percentages)
Mineral Lab Chemistry (results in percentages)
*XRD: X-Ray Diffraction analysis
*XRF: X-Ray Fluorescence analysis
Follow Up Research and Advice
In 2008, on their fifth trip to Japan, the Duffs visited more shino potters to get advice about how to improve their results. They were introduced to Tateki Kawaguchi and Shotaro Hayashi, two highly regarded shino potters. Shotaro suggested the use of saggars and a slower firing. Kawaguchi generously offered Duff some of his Mogusa clay to try in her kiln so she could compare it to her North Carolina shino clay body. According to Duff, “Mogusa is a very sandy kaolin clay that remains porous after firing.”
Upon returning home, Duff made saggars for the seventh firing in 2009. The results of this firing were not distinctively or qualitatively different from pots from the previous firings. However, when the Mogusa clay and feldspars from Japan when seen next to Duff’s clay body and glazes, the results were markedly similar. On Duff’s 6th trip to Japan, Taketi gave her more Mogusa clay, which she had shipped back to the US. Currently Duff only uses the Mogusa clay for chawans in the shino kiln.
From 2009 to 2014, the shino project went on hiatus. Duff became quite busy with exhibition and workshop opportunities in Germany, France, Japan, and Korea as well as in the US.
Bringing Shino Artists to the US
During Duff’s 7th trip to Japan, in October of 2014, she talked to Michikawa and Kawaguchi about having them come to the US for a firing in spring of 2015. Unfortunately Kawaguchi could not make the trip. In May of 2015, Michikawa attended the 9th firing. Duff learned a lot more about how to fire the kiln, but she and Royle felt the results of the firing were not appreciatively better overall than previous firings. For Duff, “The best thing that happened while Michikawa was here was that he showed me how to do a Tanka firing.”
During the seven-day shino-kiln cool down, Michikawa decided to do a Tanka firing in Duff’s gas-fired reduction kiln. He took pots that had been previously fired in the shino kiln that were not quite good enough and re-fired them, building large saggars around the pots and filling them half way with charcoal. The 12-hour firing produced dramatically subtle effects and significantly improved the pots! The coloration was quiet but enhanced, with pinkish purple blushes as well as dark gray surfaces at the bottom that bleed into the upper part of the pot.
A Challenging Journey
The research that Duff has undertaken to determine the composition of Japanese shino clays and glazes as well as ways to recreate them using materials found in the US is a difficult one. It is not easy to translate the techniques and processes of another culture, not to mention the deeply embedded and complex aesthetics of the tea ceremony. Duff’s deep knowledge and appreciation for traditional Japanese shino ware, her intellectual curiosity, determination, and sensitivity to the nuances of form and surface are assets in this still ongoing pursuit of an authentic shino in the US.
Judith Duff lives and works in Brevard, North Carolina. She received degrees in biology and painting from Wesleyan College in Macon, Georgia. Since 1991, she has been a full-time studio potter. Find out more about her work at www.judithduff.com.
A Very Brief History of Shino
Condensed from Shino and Oribe Ceramics by Ryoichi Fujioka
Arakawa Toyozo (1894–1985)—the great Japanese potter from the Mino area, (near Nagoya)—and Hajime Kato, developed the first modern shino glaze by studying Momoyama Shino pots. Toyozo discovered shards from the remains of a Mino kiln site in the mountains surrounding his birthplace. He then devoted the rest of his life to making shino.
Shinos were first fired in ogama-style kilns used at that time. Ogamas are single-chambered kilns made from a trench in a hillside that was covered with an earthen roof. The ogama was replaced by the multi-chambered anagama kilns (which were introduced from Korea in the 5th century CE) during the first decade of the 17th century CE. The Mutabora, Kamashita, and Naka Kilns of Ogaya were all in production at about the same time and were responsible for the best Shino pieces.
Origins of Shino Glaze
Shino was Japan’s first high-fired white glazed pottery with iron-oxide brush markings and glazes made almost entirely of feldspar. The characteristics of shino glazes are small pinholes called sauna (nest holes) and yuzuhada, or citron skin. Historical Shino ware’s textured surface of pinholes and crackles was greatly esteemed by tea ceremony practitioners who soon incorporated it into the art of tea (chanoyu in Japanese).
The theory is that Shino ware was inspired by a white Chinese teabowl in Shino Soshin’s possession. Soshin was an incense master and active in the tea ceremony in it’s early form in the court of the shogun, who commissioned Shino bowls from Seto kilns. Another theory came from studying a tea caddy called Bamboo Grass (also pronounced shino in Japanese) owned by Soshin. The term Shino came into use around first decade of 18th century. Shino teabowls closely resemble pottery form South China and South Asia—only the clay is different.
Shino originated during the Momoyama period (1573–1615), an age dominated by the importance of the tea ceremony. Great tea masters Takeno Joo, Sen no Rikyu, and Furuta Oribe were enthusiastic about Shino ware, and they set the standards for the tea ceremony ware and creating a demand for Shino pots.
(Source: Shino and Oribe Ceramics, Ryoichi Fujioka, 1977, Kodansha International)
the author Stephen Driver is a ceramic artist living in Ozark, Arkansas. Learn more about his work at http://littlemulberrygallery.com.