First, it is fired at 1050°C. After enamelling it with oxides, it is fired a second time at 960°C.
As soon as a red hot piece of ceramic is taken out of the kiln, it is placed in a big tin container filled with sawdust that gets on fire.
The thermic shock causes cracks that become black with the smoke. The piece is then put in water to set the design.
It is the passage from the fire to air which determines the type, quantity and size of the cracks and the tone of the colours. This firing technique is harsh : between 30% and 50% of the pieces break when they are taken out of the kiln.

Since "Raku" ceramic pottery is baked at a low temperature, compared to porcelain and sandstone, it is slightly porous.