The raku firing process evolved in Japan along with Zen Buddhism and the Japanese tea ceremony.
A raku firing is an amazing and dramatic process to behold. The procedure requires great skill - it puts the potter in direct contact with pieces approaching 1800 degrees Fahrenheit - but when carried through successfully, it can create some of the most vivid colors, powerful luster and dramatic bare surfaces in ceramic art. The firing involves rapidly heating glazed pots to approximately 1800 degrees Fahrenheit over three to four hours and then removing them from the kiln at their peak temperature when the glaze is molten and the clay is radiant orange. Hot pots are placed into a pit or barrel lined with combustible material, in this case newspaper, which bursts into flames, producing a thick, black smoke that is absorbed into the porous clay. The barrel is then sealed and the pots are left to cool, or reduce, in the barrel for several hours. This reduction process is what creates the variety of remarkable and beautiful fluctuations of color in the glaze. When the pots have cooled, smoke and ash are scoured away to reveal vibrant colors and crazing in the glaze surface.
