Pottery, one of humanity's oldest crafts, has evolved significantly over the years. Modern potters have a varied range of clays at their disposal, each suited to different techniques and outcomes. However, today, most professional potters use manufactured clays in their production. This means they do not dig in ditches and rivers to obtain their clay. Instead, they order boxes of clay from a supplier that has blended different raw materials to produce a clay perfect for production.
What are the different types of clay?
Understanding these materials and why manufactured clay is preferred today says a lot about the artistic and practical aspects of contemporary pottery. But first, here is a brief description of the different types of clay used in pottery:
Earthenware: This is a common and versatile type of clay, fired at lower temperatures (approximately 1,000 to 1,150 degrees Celsius). It is known for its porous nature unless glazed. Earthenware is often red or brown and is much more fragile than stoneware and porcelain. Earthenware is commonly used for decorative objects, flower pots, and traditional tableware, and its rustic appeal makes it popular in artisanal pottery.
Stoneware: Fired at higher temperatures (approximately 1,200 to 1,300 degrees Celsius), stoneware is durable and non-porous. Its color ranges from light gray to buff or brown, and it is ideal for functional objects including baking dishes, mugs, and plates. Its ability to retain heat makes it an ideal material for cooking and serving food. Because of its strength, stoneware is prized by potters for its practical and aesthetic qualities.
Porcelain: Porcelain is a high-temperature clay (approximately 1,300 to 1,450 degrees Celsius) known for its whiteness, translucency, and fine texture. The high firing temperature vitrifies the clay, making it extremely hard and glass-like. Like stoneware, porcelain is non-porous, even without a glaze. Porcelain is often prized for fine china, decorative objects, and high-quality tiles. Its elegant appearance and ability to be shaped into very thin and delicate forms make it a preferred material for luxurious and formal settings.
What is manufactured clay?
Manufactured clays have been around for almost as long as potters themselves. The ancient Mesopotamians and Egyptians, for example, created pottery from prepared clay as early as 4000-3000 BCE. These early potters refined raw clay by removing impurities and adding materials to improve workability and durability.
Today's manufactured clay is a refined and specially formulated material. Although the materials themselves are extracted from the earth, the result is a clay that is not found in the wild. It is made from a blend of natural clays and minerals such as kaolin, feldspar, and silica. These raw materials come from various geological deposits around the world and are selected for their specific properties that contribute to the desired characteristics of the clay.
So, why do we use manufactured clay?
Modern potters often opt for manufactured clay for several compelling reasons, all related to saving time, money, and energy:
Consistency and quality: Manufactured clay is processed to ensure uniformity in particle size and composition, which results in consistent performance. This regularity is essential for producing high-quality pieces. Natural clays can also contain impurities such as rocks, organic matter, or harmful minerals. Manufactured clays are purified and sifted to remove these contaminants, resulting in a safer and more reliable material.
Availability and convenience: Natural clays can be irregular and difficult to find. Manufactured clay is readily available in various formulations, allowing potters to save the time and effort required to source and prepare raw materials.
Enhanced properties: Manufacturers can improve the properties of the clay by adding materials that enhance plasticity, firing range, and durability. These custom-made clays offer potters a wider palette of characteristics to suit different techniques and creative visions.
The rarity of wild stoneware
Stoneware, with its specific mineral composition, is also relatively rare in nature. Most natural clays are closer to earthenware due to their higher iron content and lower firing temperature. The qualities that make stoneware desirable—its strength, durability, and vitrification—are best achieved through careful control of the clay's composition and firing conditions. Such control is rarely possible with raw, unprocessed clay. Even if one were to find a natural stoneware with the right composition, it would require significant processing to transform it into usable stoneware. This involves removing impurities, obtaining the correct particle size, and sometimes mixing it with other materials.
Does wild porcelain exist?
No, porcelain is not found in the wild. Although the primary raw material for porcelain, kaolin (a type of white clay), exists in nature and can be found in various parts of the world, porcelain itself is a refined product. To create porcelain clay, kaolin must be extracted and then intensively processed to achieve the fine particle size, purity, and specific mineral composition necessary for the unique characteristics of porcelain. This processing includes the removal of impurities, blending with other materials such as feldspar and silica, and sometimes adding specific additives to improve its properties. Consequently, all porcelain clay used by potters is a manufactured product.
Conclusion
Although the romance of clay extracted from the earth persists, the practical aspects of modern pottery largely favor manufactured clays. These provide potters with reliable, high-quality materials that allow for consistent results and foster creative exploration. The ancient art of pottery therefore continues to thrive, seamlessly blending tradition with modern innovation.
