Clay – the most primitive natural raw material for pottery

In Vietnam, pottery making is often referred to as a light entertainment activity – usually a one-time trial, but few people pursue pottery as a long-term hobby. When it comes to pottery, usually people will mention traditional names such as Bat Trang, Minh Long; There are not many artists specializing in making or selling pottery even in small quantities or with a clear and strong personal mark on their products. Last time I had the opportunity to learn about pottery, and the more I understood pottery, the more I found it interesting and fascinated by this art. I will try to systematically and regularly post blog posts – as this is also an effective way to organize what I learned about pottery. 

In this first post I will share a few brief summaries of clay – the main raw material for making ceramics. Clay is the most basic, primitive natural material of pottery. Potteryists can use 100% natural clay, or industrial clay – which is blended from raw materials in certain proportions.

Different ratios produce different types of ceramics:

• Different in color: ceramics can come in many colors: from white, ivory, yellow earth, to gray, black, magenta, orange, red brown earth.
• Different in uses: 100% hand molding, molded liquid clay, turntable clay, sculpting clay, and more.
• Different in other physical properties: plasticity, shrinkage
• Maturity temperature difference: Each ceramic has a different maturity temperature, maturity temperature, which is the temperature at which the clay becomes the hardest, “densest” clay after undergoing the whole heating process. from normal to ripening. If only heated below the ripening temperature, the ceramic will be weak and porous – it can be water absorbent. If overcooked, the ceramic can warp or even break.
• The end product also varies in hardness, density, transparency – the ability to pass light (translucence), etc.

There are many ways to classify clays, but perhaps the most common for studio pottery makers is the classification based on the ripening temperature of the soil:

• Earthenware: the temperature is about 1000-1180 degrees Celsius.
• Stoneware: the ripening temperature is about 1200 – 1300 Celsius.
• Porcelain: 1240 – 1350 Celsius.

The harder the clay is heated at high temperatures, the harder and heavier the final product. Porcelain is the lightest type of ceramic, and is usually the most fragile. Potato is often used for outdoor furniture, such as potted plants, water jars. The most common color of china is reddish brown – from light to dark (but there are other varieties of white or gray). Ceramic is stiffer, more common, and is most commonly used by those who prefer to create products 100% by hand. Pottery is the most common color is ivory white or slightly to beige, but there are also white, gray, red, even black. Porcelain is the hardest type of ceramic; When a certain thinness is reached, light can pass through the material. The most common color of porcelain is cold white, there is also a black ceramic, but the use of black ceramics is relatively rare because often making ceramics / porcelain wants to take advantage of the outstanding and unique properties of the porcelain, which is the surface. glossy, pure and white.