The Making of Celadon
Celadon production is a relatively long and complicated process as it is carried out in Thailand. The most essential aspects of production are the use of the proper earthenware clay raw materials, proper drying, the use of highly skilled artisans in moulding and design application, and the glazing and firing processes. A small, comparatively simplistic design, either hand-painted or in low relief, usually takes four to six weeks to make well. A larger piece in sometimes highly intricate designs can take as long as ten weeks, although six to eight weeks is the average. The following is a brief guide to the Celadon production process.
Step 1: Dried earthenware clay in raw form is reduced to powder and then filtered through a sieve to make sure all elements of the base material are pure clay in powder form.
Step 2: This powder clay is then passed through what is called a pug-mill -- the pug-mill is a hand-driven machine of sorts which further crushes and blends the powder clay in order to make it more malleable for structural formation, and in order to make it more solid and dense in its final form. The powder clay is mixed with water prior to processing through the pug-mill.
Step 3: After having passed through the pug-mill, the now moist clay is left to age for a short period of time in the open air, where the aging process takes place through a natural interaction of common bacteria carried by air with the moist clay.
Step 4: After proper aging, the clay is kneaded in order to remove air bubbles that form during the aging process, and in order to improve elasticity and plasticity.
Step 5: The clay is then ''Thrown-on-the-Wheel'', a term which means that the clay is hand-moulded with the help of a rotating cylinder which forms the interior of the Celadon piece. The exterior surface, the edges, and the base are all hand-formed.
Step 6: After each piece has been moulded, it is set aside and allowed to dry, again in the open air, until it gains the hardness and comparative consistency of leather. In Celadon production this is called ''Leather Hard''.
Step 7: When ''Leather-Hard'' the clay pieces are hand-engraved, incised, carved or painted using often intricate designs and motifs. They are then left to dry completely in the open air. When quite dry, they are checked for cracks or defects of another nature. Note: Although at this point in the production process the pieces are hard and dry, if immersed in water they will quickly revert to the base clay with no form or design.
Step 8: All pieces passing inspection are then ''Bisque Fired'' in a tub kiln to a temperature of approximately 800 degrees Celsius. At this point the bisque-fired pieces are stable in water but are still porous. A second check is made for cracks or other defects.
Step 9: The bisque-fired pieces that pass inspection are dipped in a special Celadon glaze. This glaze is usually made of rice stalk, bean stalk, or bamboo mixed with the ash of various types of tropical wood. After dipping in the glaze, it is set and allowed to dry.
Step 10: The final step is to fire the pieces, already glaze-dried, at the ideal temperature range of 1,260 to 1,300 degrees Celsius in carefully controlled and monitored ovens.
See related articles (Ceramics, Celadon, and Pottery):
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