Japanese crack glaze is a type of finish created by the combustion of metals, rich in colour and a big feature within Japanese culture. It's often associated with raku pottery, which was traditionally used for Japanese tea. However, it has since evolved to be made in vases, animal figures and more. The unique and beautiful Japanese crackleglaze designs, inspired by the traditional Japanese raku firing process, means the pottery is great as aesthetic pieces, tableware, and gifts.
The History of Raku Pottery
Since the 16th century, the Japanese have been creating beautiful and authentic raku pottery with a crackleglaze finish. The creation came from the tile maker Chōjirō who was instructed by Zen tea master, Sen Rikyū, to create pottery for his tea ceremony. The raku wares are unique from anything that came before it as Chōjirō modelled the tea bowls by hand, unlike previous pottery which had been created on a wheel. The diverse shapes and colours of raku crackleglazed pottery are influenced by the makers hand and also an essence of luck as the cracking effect is made through the cooling process. This unique method of creation, explained in detail below, is what makes these pieces stand out from other pottery and why it is still loved and appreciated today. How is Japanese crackleglaze made?
Traditional Method
The traditional process of raku pottery placed pottery under the extreme stress of temperature changes. Unlike normal pottery pieces which are matured in a cold kiln, raku pottery is placed in an extremely hot kiln and then quickly removed whilst still hot. This is the beginning of its uniqueness. The piece is then rapidly forced to cool either in the air or in water. The original Japanese method of natural intense cooling creates the beautiful effect of cracking. The word raku translates to 'enjoyment' and 'happiness in the accident', emphasising how naturally beautiful this pottery is.
Modern methods
The modern methods method has been influenced from the traditional and incorporates the intense cooling, which gives the pieces their beautiful crackleglaze finish. In modern techniques, the pottery is removed from the hot kiln and placed into containers with combustible materials that ignite. The metallic compounds give the pieces their vibrancy through glazing with colour. For example, cobalt produces a dark blue and copper can produce green, but also red when oxygen is absent in the glaze. The intentional cracking comes from the thermal shock, and means no Japanese crackleglaze piece is identical.