The word “raku” means “happiness in the accident.” Originally created for the Korean tea ceremony, this technique was subsequently found by ceramic adherents in the sixteenth century in Japan, where the great masters such as Sen no Rikyu were able to give full scope to the art based on a particular process: the fast removal of the piece from the furnace and covering it with flammable materials like natural wood sawdust to inhibit the absorption of oxygen to the molten enamel, which produced the characteristic cracking effect from the thermal shock. Also the colors were rendered with a more metallic appearance .
The unique look of  Japanese Raku pottery is achieved by utilizing  both smoke and fire in the Raku kiln to create an unpredictable and unique style. Firstly the pottery is bisque fired , than glazed and fired in a Raku Kiln followed by enhancement in a reduction chamber. As opposed to normal pottery firing where the wares cool down slowly in the kiln and removed with gloves, Raku ware is removed immediatly with tongs.
Glazing : Raku pottery can be produced from any clay, but if you use the special Raku clay it is more suited to withstand higher temperatures and thermal shock. After placing the completed piece in a kiln and firing it, you apply the Raku glaze by either spaying, brushing or sponging . The above image displays a Raku piece with copper added to the glaze. Some of the Raku glazes produce cracking and result in a spider webbing effect. Also you can combine both a glazed and unglazed natural smokey effect on the pottery
Removal of Raku Pottery from a kiln.
Raku Firing : The first step of bisque firing hardens the clay and needs a level of at least clone 08. Then the glaze is applied and virtually any low temperature glaze is appropriate for Raku. The next step is to fire in a Raku kiln ( F 1800 ) and leave for around 30 minutes before placing in the reduction chamber. A metal can with a lid can be used for this stage, even a metal rubbish bin will work ok and  the pottery can remain in this chamber for  15 to 90 minutes. Combustible material such as wood, newspaper, cardboard and dried leaves can be used, they all produce a different effect. The smoke from these  materials all contribute to changing the colors and patterns of the Raku pottery. The intrigue of applying this Raku style is in the random results you can obtain. You can even use a water mist in the cooling process to influence the final colors.
Reduction on a bed of vegetable matter
The final stage is to dunk the piece in cold water and clean with a stiff brush or some abrasive material to remove the ash. Raku pottery is mainly used for decoration rather than being functional.
Raku pottery was first developed by Japanese potters in the 16th century and it still holds a mystique and is embraced by amateur and professional potters till this day. The appeal of Raku was heightened in Japan when the ware was created for use in Japanese tea ceremonies.
Japanese Raku
A vase glazed and fired using the Western Raku technique, showing the soot, crackle glazing, and random oxidation typical of this pottery form.
More Raku see French Raku Studio
