Spark visits with Ikeda in his studio and at a "noborigama" in Napa County, which is a 30-foot wood-burning kiln that is kept burning for seven days straight. Such kilns have been used in Japan since the 17th century. The noborigama's wood-firing technique produces a unique natural ash glaze. Like most ceramicists, Ikeda has developed his own distinctive styles of glazing, formulating personal recipes such as the refined "sei shya," or blue rust, which he uses on his dappled, woven baskets. But it is the philosophy of the age-old ikebana that most clearly informs his work in clay, which can be intricate or simple, highly finished or naturalistic.