Clay is the basic work of Jianshui purple pottery technology, and also the key first step to determine the quality of pottery.
We all know that the clay of the water building pottery comes from the five kilometers west of the bowl kiln village. There are five kinds of soil in five colors in wucai mountain, which are red, yellow, green, purple and white. The clay is fine, gelatinous and oily, but once it leaves the mountain, it will be affected by weathering and become hard as stone.
It should be noted that not all the colored clay is of high quality. The clay of Jianshui pottery appears in the form of associated minerals in the mountain. Therefore, the selection of clay needs the eyes of the old artists. Only those high-quality and pure colored mud with pure and natural color, fine soil, pure and no impurities, can adapt to the special process of Jianshui purple pottery and produce exquisite products Excellent purple pottery of Jianshui.
Firstly, the selected multicolored clay is stacked in different colors, weathered and dried, and then crushed into powder form, so that it can be better dissolved in water. After screening, coarse sand impurities are removed, different powder original soil is mixed according to the requirements of pottery making, and then put into the tank and add water to make slurry.
After mixing and washing, when the sand mud is sunk at the bottom of the cylinder, the slurry above is filled with a spoon and poured into another cylinder for re washing, and the sand is filtered. After repeated 5 or 6 times, the mud which is already greasy as cream and no sand particles is put in the closed state and naturally coagulates to dry into mud.
Therefore, Jianshui clay is also referred to as bleached mud. Before each pottery making, craftsmen must carefully prepare different colors of clay, because the color of Jianshui pottery is completely made of natural clay, and the proportion of different colors of clay depends on the experience of craftsmen.
Because each batch of soil is located in different sedimentary zones of the mountain, the natural aging time of the original mud is very large due to the difference of the height of the mud taken (the formation and change of the mountain are often tens of thousands of years). Even if each batch of soil has the same formula, the final firing color is also different, which is different from the formula mud used in Yixing and Jingdezhen, because the original mud of Jianshui pottery is in the middle of the mud The change of surface elements makes Jianshui clay unstable and uncontrollable.