• by vinux

Yixing purple clay pottery is a traditional craft of Jiangsu province and one of the most famous ceramic crafts in China. As with any industry, there are many technical terms related to the Yixing purple clay pottery. Here is a brief introduction to some commonly used technical terms in this field.

“Touzi”, also known as “Xuanzi” or “Yin Zaozi”, refers to a kind of round or oblate kneaded ball made from clay which is used as the raw material for making Yixing pots.

“Sha” refers to the process during which the raw materials are ground into very fine particles and then mixed together with water or other liquid mediums. This process is essential for making a certain type of clay that has superior properties such as strong air resistance, waterproofness and elasticity.

“Fuhe” means grinding the surface of a finished product until it is smooth and uniform using special tools such as grinders and engravers.

“Jiawei” means adding decorative patterns on the surface of pottery products using traditional methods such as luting, carving, pressing and coloring.

Finally, “Diaoqi” refers to the firing process during which pottery objects are heated inside an oven at high temperatures for a period of time. This process can alter the chemical composition of objects and improve their physical properties such as strength, color, texture and durability.
Zisha art is rooted in arts and crafts, drawing from traditional culture and mediated by tea culture to gradually form its own unique ceramic art. Whether in China or around the world, Zisha art is unique, distinctive, stylish and unprecedented. Yixing has its own unique resources with special properties. The wisdom of the craftsmen creates a unique process of forming and shaping craftsmanship as well as unique techniques. In the industry, a lot of professional terms have also been formed which many novices are unaware of. Today, small editions introduce you to some common industry jargon:

Tea Mountain: Purple sand teapots have good permeability, and when used for a long time, the tea traces adsorbed in the pot are usually referred to as the tea mountain.

Stale: Also known as “cultivating soil”, it is the last processing step of purple clay mud material. The mud material which has been blended and kneaded will be placed in a pottery cylinder and set in a damp place to allow it to age and mature.

Maturation period: The time from storing the kneaded and shaped clay in a damp and shaded place is called the maturation period. Just like vintage wine stored in an underground cellar, the longer the maturation period, the glossier and more elegant the jar will be. The maturation period must last at least three months.

Patina: After years of use, a layer of natural and special luster forms on the surface of the teapot. This luster is restrained and deep.

The “Sunray Line”: At the bottom of a purple-clay teapot, with its surface center radiating outwards, like rays of sunlight, is called the “Sunray Line”.

Polishing the inner wall: When the inner wall of a purple sand teapot is uneven during the forming process, in order to make it smooth and even, workers use tools to tidy up, which is called “polishing the inner wall”, and this method is most commonly used for mold teapots.

Weathering: The extracted ore is stacked in the open air and subjected to the sun and rain of nature, wind and rain, extreme cold and heat, collapse and disintegration, which makes the original dense block change into loose particles. The texture changes from hard stony structure to soft soil structure. This process is called “weathering”.

Raw materials: Materials mined and extracted are commonly referred to as “raw materials.”

Mature ore: Ore that has been sufficiently weathered for at least three months or more is referred to as “mature ore”.

The number of meshes: After mining the purple clay ore, it is weathered, removed impurities and crushed, and then screened and filtered. The coarseness of the mud after this process is called mesh number. This process is also called sieving. Mesh numbers have a history as well – 26-35 meshes during the mid-Song Dynasty; 35 meshes during the early Qing Dynasty; 55-60 meshes during the mid-Qing Dynasty (since manual crafting was used before 1957, mesh numbers were relatively low resulting in better permeability, coarser particles and stronger texture for purple clay teapots, which is also one of the standards for distinguishing old teapots). Mechanical sieving began in 1958 with mesh numbers being roughly around 60. Raymond pulverizers with wind control to regulate mesh numbers have been used since 1959 and can reach up to 140-180 meshes. Nowadays, different mud crafting methods are applied to make purple clay teapots with basic mesh numbers remaining at around 60. With 60 as a benchmark, a greater relative mesh number indicates finer mud while a smaller one means coarser mud.