Smooth and Exacting Surface Decoration Sumiko Takada with Kaname Takada

Appears in the March 2017 issue of Ceramics Monthly.

I was born and raised in Nagoya, located in a region rich in the ceramics culture and tradition of Japan. Seto, arguably the most famous town for ceramics in Japan, is a mere 30-minute train ride from my house and other towns like Tokoname, Tajimi, and Iga are all nearby. In this environment, my interest in ceramics began at an early age but it took me years to get my hands in clay seriously. When my son started attending a nursery school, I started taking classes offered at the studio of a local ceramic artist, Mr. Yasunori Nishio. I was 30-years-old and wanted to make pots I could use in my house. Nishio was also the one who introduced me to inlaying, but at the time it was one of the many techniques and processes he taught me that I didn’t expect would later become an important part of my creative life.

My approach to working with inlay techniques was somewhat roundabout. About 15 years ago, I was working on cobalt decorations on a white clay body, making pieces like Sometsuke ware in a continuing education class at a local college but I was not happy with the result I was getting. Around the same time, a friend let me use her slip trailer to create designs with blue slips on greenware instead of cobalt washes on bisque ware. The slip trailer was easier for me to use than brushes and I made several pieces with slip-trailed designs on a white background under a clear glaze. Though I liked the process of slip trailing, I didn’t like the raised designs. I wanted the surface of my pieces to be flat and smooth. That’s when I remember the inlay technique I was introduced to at Nishio’s studio. I tried it and I was really pleased with the result. I also found that the process of inlaying is much more satisfying for me. It took more time than brush work to complete, but it seemed to fit my personality as a potter better.

The reasons for switching from a white clay body to a dark clay body were both practical and aesthetic. While working with the pieces, I found that it was hard to remove all of the excess cobalt slips on the white body. Speckles of blue seemed to be always present on my pieces no matter how hard and carefully I cleaned. So, I tried inlaying on a darker clay body and found that the blue speckles were not so visible. Also, the unglazed surface of the darker clay body was more visually appealing to me. Though there were changes of firing temperature and atmosphere from cone 10 reduction to cone 5 oxidation, creating unglazed, inlaid designs on a darker clay body has been my body of work for the past 15 years.

4, 5 Trace over the transferred lines with a needle tool to make them deeper, then use a double-ended ball stylus and small wire loop tool to make the pattern wider and deeper.

My primary method of forming is wheel throwing. I make pieces for inlaying a bit thicker than other types of work as I feel safer and more comfortable working on them as greenware. My current clay body has a fairly large percentage of Cedar Heights Redart clay for the color. I have tried other bodies, but so far it fulfills my needs best with its color as well as its texture, which is fine enough not to cause scratch marks on the surface as I remove excess engobes with a metal rib. I use Columbus Clay Engobe from our local supplier, adding oxides and stain colors. As the exteriors of my pieces stay unglazed, the only glaze I use is a white liner glaze.

Motifs for my inlaid designs come from various sources but are influenced most by traditional Japanese geometric and floral patterns found in many common objects people use in their daily lives.

I prepare stencils of pattern designs on tracing paper using pencil (1). The sizes and proportions of the patterns are adjusted depending on the shape and scale of the pieces. Though I have favorite pattern designs, I am always looking for new ones and regularly add two or three new patterns to my repertory.

Grid lines are drawn as the reference on trimmed, leather-hard pots (2) and then patterns are transferred on the piece using a needle tool with a rounded tip (3). I apply just enough pressure to draw lines on the paper without tearing it. I can usually use a paper stencil over 20 times.

Carving starts with tracing transferred lines with a needle tool to make them deeper. Then a double-ended ball stylus and small wire loop tool are used to make the pattern wider and deeper as the leather-hard ware dries (4, 5). Generally speaking, the carvings are linear and their depth is no more than ¹⁄₁₆ of an inch. Wider and deeper carvings may result in cracks between the body and engobe. I pay close attention when drying my work and with the timing of carving as it is hard to make clean lines with an even depth and width on the surface if it is too soft or too dry. Depending on the sizes of pieces and the complexity of patterns, it takes a few hours to a few days to complete the carving.

After the carving is completed, engobes are applied with a fine-tipped slip trailer (6). Over the years I have tried different types of trailers but the inexpensive plastic trailer seems to work best for me. With metal ribs, I do an initial cleanup of excess engobes when they are drying but still softer than the clay underneath, which makes the engobe easier to remove (7). When the engobes dry to the same stage as the clay, the final cleaning is done carefully without disturbing the surface (8).

Between bisque and glaze firings I clean up the surface once more with 320-grit sandpaper (9). Final sanding will ensure the smooth and clean surface of the fired pieces.

After sanding, a white liner glaze is applied to the interior (10) and the piece is fired to cone 5. My firing is simple, I use the cone fire mode on our Skutt kiln, choose medium for the firing speed, and add a hold of 15 minutes to the end of the firing.

Other than a brief introduction at Nishio’s studio and technical help from my husband, Kaname, with clay and glaze formulation, much of what I practice with the inlaid work has been self taught. Though it was frustrating at times, it has been an enjoyable and rewarding experience. There will be always something new I want to try on my pieces and I can’t wait to make the next one.

the author Sumiko Takada has been working in clay for over 15 years. She has studied in Japan with Yasunori Nishio and Jun Terada, both in Komaki, Aichi, and in the US at the Worthington Community Center and at Columbus College of Art and Design. See more of her work at www.studiotakada.com.