By Val Naber
The origin of porcelain can be traced back as early as 7000 BC, when cave dwellers in Turkey made bowls, jugs, and utensils out of clay.
In 5000 BC, Egyptians built ovens to improve the quality of the clay pieces.
The technique of Over Glazing was not discovered until 3000 BC. This technique gave the clay a protective coating, helping to prevent disintegration, breakage, and absorption of the clay.
In China, the T’ang Dynasty in 618 AD began making what is known today as hard porcelain. This porcelain was created by mixing combinations of Kaolin clay and Feldspar. Distinguishable characteristics of this porcelain include:
- Hardness or Bitimus
- Whiteness of the body or paste
Any ceramic piece that possesses all of these qualities may be classified as porcelain, and from a practical point of view, the more it excels under these characteristics, the better the specimen of porcelain it is.
The Chinese, being supreme secret-keepers, remained the masters and sole producers of hard-bodied porcelain until the middle of the 1700s.
It was suggested that Marco Polo was the first person to introduce an example of the Chinese hard paste porcelain to Europe when he brought a piece in the shape of a vase back to Italy in 1295 AD.
Trade with the Far East at the beginning of the 15th century, brought the white translucent ceramic material to France, Venice, and Portugal. It was considered very valuable and luxurious.
The secret behind the manufacturing of this porcelain made it even more desirable.
How is Porcelain Made?
Slip, a liquid clay, is poured into a mold, filling the inside of the mold completely. The mold is allowed to sit for three to ten minutes, which allows the moisture from the slip to release into the mold, creating the cast of object. The longer the slips stays in the mold, the thicker the cast will get.
The excess slip from the mold is then removed by placing the mold upside down, draining the unset slip into a container.
The formed object is very fragile and wet. The piece needs to dry out before anything can be done with it. This may take up to 3 days.
Once the item is dry, excess material from the mold opening is cut off and lines from the mold pieces are sanded off. At this point, the piece can be manipulated by creating openings or carving designs into the cast, and then it is fired in a kiln.
Once the kiln is done firing, the porcelain needs time to cool off. The kiln cannot be opened until it reaches room temperature, about 12 hours. The cooled porcelain is then sanded or buffed to create a smooth porcelain product which is ready for painting.