Shigaraki ware is pottery and stoneware made in Shigaraki area, Japan. The kiln is one of ‘The Six Old Kilns’ in Japan. Although figures representing the Tanuki are a popular product included as Shigaraki ware, the kiln and local pottery tradition has a long history.
The local sandy clay from the bed of Lake Biwa has a warm orange color, and makes very durable pottery. This clay characterizes Shigaraki ware. The ceramics have irregular contours and an archaic flavor. Firing technique shifted from reduction to oxidation firing, which allows free admission of air during the firing rather than limited air admission into the kiln. This allows iron oxides to be used as part of the coloring process. The allowance of free air is due to the type of ancient kiln, called an anagama kiln, which is used to fire Shigaraki ware. The term anagama is a Japanese term meaning “cave kiln”, as these kilns were usually constructed into the side of hills. They are single chambered structures with a sloping tunnel shape. The wood fuel must be constantly supplied in order to achieve temperatures high enough to fire the clay. Using this type of kiln also achieves the mineral glaze surface so popular with Shigaraki wares.
Depending on the placement of the piece, the resulting coat of ash and minerals will vary. An oatmeal appearance is usually the result, with a greyish to a reddish-brown colorizing the body. Small impurities protrude, caused by embedded quartz partially fired. Covered with a thin layer of overrun yellowish-brown to a peach blossom red color glaze that crackles when fired is also characteristic of the fired stoneware. A light, transparent, or almost glass-like glaze with a bluish-green tint also appears on some Shigaraki wares. The glazes were dribbled, sprayed or spattered over the ceramic surface. Unless allowed to gather in small pools, the glaze appears near invisible in most lighting, only becoming visible when the piece is held and turned in the hand. The ware also reflects geta okoshi, the clog marks, where the clay rested on supports inside the kiln before firing. Another characteristic of Shigaraki ware is fingerprints left behind by potters in the construction process.