Raku ware (raku-yaki) is a type of Japanese pottery that is traditionally used in the Japanese Tea Ceremony, most often in the form of tea bowls. In the traditional Japanese process, the fired raku piece is removed from the hot kiln and is allowed to cool in the open air. The familiar technique of placing the ware in a container filled with a combustible material, introduced by Paul Soldner, is not a traditional Raku practice. Raku techniques have been modified by contemporary potters worldwide. Raku means “enjoyment”, “comfort” or “ease” and is derived from Jurakudai, the name of a palace, in Kyoto. That was built by Toyotomi Hideyoshi (1537–1598), who was the leading warrior statesman of the time. The Raku technique has been recently adopted in Europe and changes fundamental principles.
The surface is decorated with metallic lustre which is one of the details of the Raku Technique. During the process there is a strong thermal shock, which requires a very good quality of white Earthenware clay. Pieces are made and bisqued with an electric kiln to 950-1000°C, after that the surface decoration is added. In this type of technique, colours are oxides and glazes. For example, to have a green colour it is necessary to use copper oxide and not a green pigment. Raku kilns are like incinerators with fibre ceramic inside, where temperatures are 950°-1000°C. When the pieces inside the oven become orange the glaze is ready and the pieces can be extracted. The Kiln is opened and pieces can be extracted with tongs, left in the air or dipped into water to cool.
Water is consistent with the real Raku technique. In the 70’s this technique was modified as when the pieces were extracted, they were put in metal bin’s with combustible materials inside. With this technique, there is a high reduction of oxygen so the clay can absorb all the smoke inside the bin. After this process, the pieces are dipped into the water and cleaned to remove all burnt residues. The process of reduction can be partial or complete. When there is a strong reduction the clay becomes completely black, but if there is a slight reduction the clay can take lots of shades of grey. The spirt of Raku embraces the 4 elements: Earth, fire, water and air and will be creating unique objects as nature creates.