How to make ceramic mugs in China
Our ceramic mugs start in the mind of their beholders. Using clay, the cup takes shape on the potters wheel. A number of pots will be hand thrown, dried and fired in order to choose the most pleasing design.
The tool and die process starts with a finished cup that has been selected. Since clay shrinks when it is dried and fired, a new cup must be hand thrown a carefully calculated amount larger to compensate for this shrinkage. This becomes the model, which will be cast in plaster.
Individual molds are cast in plaster. They will be carefully dried and then placed on the casting bench.
Casting. Liquid clay called slip is poured into each mold. As the plaster mold absorbs water, the wall of the cup is formed. When the wall thickness is correct the remaining slip is poured out and recycled back into the slip tank. The time the slip must remain in the mold varies according to the slip, how wet the mold is, and even the weather. After several hours the cup is dry enough to be removed from the mold without warping it.
After the cup has dried the seams are cleaned with a knife and smoothed with a sponge.
The coffee mug is thoroughly dried and then dipped in a clear glaze.
Next the mug is loaded in our gas-fired kiln. It will be fired to about 1300 degrees Fahrenheit over an eight-hour period.