What Are The Things Clay Can Be Used For?

Clay is a natural, earthy material made up of fine-grained minerals like silica, alumina, and iron. It is soft and malleable when moist but becomes hard, brittle, and non-plastic upon drying. Clay has been used by humans for thousands of years due to its abundance, versatility, and unique properties.

When moist, clay can be molded into virtually any shape. Once it dries, it will maintain that shape and harden. This makes clay ideal for creating pottery, sculpture, bricks, tiles, and more. Clay is also heat-resistant, so clay objects can be fired in a kiln to increase their durability and strength.

In addition to arts and construction, clay has numerous other uses. It is utilized in industry, medicine, sports, cooking, and more. This versatility arises from clay’s adaptable nature and ability to absorb, hold, and release materials mixed with it. Let’s explore the many ways that this natural material enriches human life.

Pottery

Clay’s plasticity when wet makes it an ideal material for shaping and molding into pottery. Potters can throw pots on a wheel or handbuild vessels by techniques like coiling, pinching, or slab construction. Clay maintains its shape as it dries and can then be fired in a high temperature kiln, transforming it into a hard, durable material.

There are several different types of pottery firings that create diverse surfaces and effects on the clay. In a low-fire bisque firing, the clay objects are heated to around 1800°F, driving out any moisture and making them easier to glaze. Glazes are mixtures of minerals and compounds that melt and fuse to the bisqueware surface when fired again at higher temperatures around 2200-2400°F. Raku firings involve taking red-hot pots out of the kiln and placing them into containers with combustible materials like sawdust to create dramatic crackled surfaces. Pit firing relies on burning wood to heat the pieces, resulting in lots of carbon trapping and smoking effects on the clay.

Clay pottery has an extremely long history, dating back over 20,000 years to early human civilizations. Ancient Greek potters created iconic red and black figure pottery with intricate painted scenes fired on the surface. Chinese porcelain allowed very thin, translucent vessels to be produced and decorated with vibrant cobalt blue glazes. More recently, influential ceramic artists like Bernard Leach and Shoji Hamada popularized a rustic, handcrafted style of pottery in the 20th century.

Sculpture

Clay has been used for millennia to create stunning sculptures and three-dimensional artworks. The soft, pliable nature of clay makes it an ideal medium for sculpting. There are several techniques that sculptors employ when working with clay:

Clay modeling – The clay is shaped by hand, pushing, pulling, pinching and kneading it into the desired form. Modeling clay remains soft and pliable.

Carving – Sculptors carve shapes and figures from blocks of clay by removing material. Carving works well for creating intricate surface details.

Coil building – Long coils or ropes of clay are stacked and joined together to build up the sculpture. Coils can be smoothed together or left to show the rough texture.

Slab construction – Flattened slabs of clay are cut, stacked and joined to form the sculpture. Clay slabs lend themselves to both angular and curved forms.

Some of the world’s most famous sculptures have been crafted from clay. From ancient Greek and Roman figures to modern masters like Auguste Rodin, clay has proven its versatility and durability as a sculptural medium.

Construction

Clay has been an integral material in construction for thousands of years. Its durability, abundance, and malleability have made it a staple in buildings across cultures and continents. Some of the main uses of clay in construction include:

Clay Bricks

Clay bricks have been used globally in construction since ancient times. Bricks can be made by hand or machine from natural clay that is shaped and then fired at high temperatures. The firing process hardens the bricks, making them highly durable and resistant to wear. Clay bricks are affordable, provide good thermal insulation, and have high compressive strength, making them ideal structural materials for building walls, pavements, and other elements.

Clay Tiles

Like bricks, clay tiles for roofing and flooring have an ancient history, adorning structures from ancient Greek temples to medieval castles. Clay is shaped and fired to produce strong, waterproof tiles in a variety of styles. Tiles can be glazed or unglazed, flat or interlocking. Their durability and aesthetic qualities have ensured the continued popularity of clay tiles in roofing, flooring, and wall décor.

Clay Plaster

Before the advent of modern drywall and plasterboard, clay plaster was commonly used on interior walls and ceilings. A plaster made from clay, sand, and binders provides a smooth, durable and fireproof surface. Clay plasters are naturally antibacterial and regulate humidity well. Although less common today, natural clay plaster is still valued for its non-toxic qualities and vapor permeability in natural building techniques.

Clay Paint

Clay has been used as a base for paints and coatings for thousands of years. Natural clay paints typically contain clay, chalk, lime, casein, and natural pigments. Clay paint helps walls “breathe” and provides natural moisture regulation. It can be tinted to any color and gives a matte, flat finish. Clay paints are gaining popularity once again as consumers seek sustainable, non-toxic options.

Industrial uses

Clay has a variety of industrial applications thanks to its ability to withstand high temperatures and absorb substances. Key industrial uses of clay include:

Refractory clay

Refractory clay is able to withstand extremely high temperatures without deforming or melting. It is used to line furnaces, kilns, fireboxes and fireplaces. Refractory clays contain a high percentage of alumina and silica.

Bentonite clay

Bentonite clay has a variety of industrial uses thanks to its ability to absorb large amounts of water and expand. It is utilized for drilling mud, foundry sand binding, iron ore pelletizing, and as a sealant for ponds, dams and other containment areas.

Casting and molding

The pliability of clay when wet makes it ideal for casting and molding materials and products. Clay is used for molding metal, glass, and plastics. It can produce very intricate and detailed molds.

Clay absorbents

Clays like bentonite and fuller’s earth are utilized for absorbing grease, oils, and animal waste. Cat litter is often composed of clay for its absorbent properties. Clay absorbents are also used to clean up spills by absorbing liquids quickly.

Medicine

Clay has been used for medicinal purposes for centuries. The earliest recorded use of medicinal clay dates back to ancient Mesopotamia. Certain types of clay are rich in minerals like silica, iron, magnesium, calcium, sodium, and potassium. Clays can also absorb toxins and impurities. For these reasons, medicinal clays have been used both internally and externally.

When clay is taken internally, it can help treat digestive issues like diarrhea, constipation, and bloating. The minerals in the clay and its absorbent properties can help soothe gastrointestinal inflammation and neutralize toxins. Some clays are also thought to boost the immune system. However, internal use of clay should be discussed with a doctor first.

Externally, clay has long been used in skin care treatments. Clays like bentonite and French green clay can help cleanse and detoxify the skin. Clay masks help remove excess oils and impurities from the skin while delivering minerals and improving circulation. The cool temperature of clay also helps soothe irritation and inflammation. Some clays have mild antiseptic and antimicrobial properties as well.

Medicinal clays can be purchased for home use. They are commonly formulated into clay masks, soaps, bath powders, and skin care products. Using a medicinal clay face mask 1-2 times per week can deep clean pores, absorb oil, and improve overall skin health.

Cooking

Clay pots and bakeware have been used for cooking for thousands of years. Cooking with clay pots has some unique benefits:

Clay Pot Cooking: Clay is an excellent heat conductor and retains heat very well. This allows food to cook slowly and evenly. Clay pots like tagines are ideal for braising meat and cooking stews. The condensation stays in the pot instead of evaporating, keeping food moist.

Clay Bakeware: Clay baking dishes hold heat evenly and gently cook baked goods. The natural clay doesn’t have a strong flavor or chemicals that could leach into food. Clay bakeware comes in many shapes like pie dishes, casserole dishes, bread pans, and ceramic baking sheets.

Modern clay cookware often has a glaze that makes it non-porous and suitable for all cooking methods. Unglazed terra cotta should only be used for certain dishes, not acidic foods. Clay’s heat retention works well for slow cooking methods like braising in the oven or on the stovetop.

Paper

Clay is an important material in paper production and coating. The fine particle size and plate-like shape of clay materials like kaolin make it useful in creating smooth, high quality paper.

In paper production, clay is used as a filler and coating pigment. It is mixed with cellulose fibers during manufacturing to improve qualities like brightness, opacity, printability, smoothness and ink absorption. The clay fills spaces between the fibers, creating a smoother, denser sheet.

Clay-coated papers, like those used in magazines and art books, have an extremely smooth and glossy surface. The clay coating provides a hard, protective barrier that improves printability. It fills in surface roughness and creates an even surface for printing ink to adhere to.

Different clays used in paper provide unique advantages. Kaolin clay improves brightness and opacity. Bentonite clay increases bulk and absorption. Attapulgite and montmorillonite clays enhance binding strength. Using the right clay for the job is important in papermaking.

Overall, clay’s natural properties make it an essential material for achieving high quality paper production and coatings.

Sports

Clay is an important material used in constructing playing surfaces for certain sports. Two of the most notable examples are baseball and tennis.

For baseball fields, clay is a key ingredient in constructing the infield which contains the bases and pitcher’s mound. A mixture of clay and sand is used to provide a firm but slightly giving surface. The clay allows the infield to be shaped and hold that shape, while also absorbing a bit of impact from players running the bases. This provides a consistent and safe playing surface. The iconic red color of baseball infields comes from the iron oxide pigment within the clay.

In tennis, clay courts are one of the three main court surfaces along with grass and hard courts. The red clay surface, called terra battue, is made from crushed brick or stone. Clay courts slow down the ball and produce higher bounces compared to grass or hard courts. This changes the playing style, favoring players with defensive strengths. Clay court tennis is a distinctive part of the sport, especially in major tournaments like the French Open which is played exclusively on clay.

The unique properties of clay make it well-suited for constructing playing fields and courts for certain sports. Its ability to be packed and shaped, provide firm traction, and absorb impact have made clay an essential material for some major sports.

Other uses

In addition to the major uses listed above, clay has found niche applications in a variety of other areas:

Kitty litter – Bentonite clay is an absorbent type of clay that can soak up moisture. It is often used for cat litter products. The clay clumps when wet, allowing easy cleaning of litter boxes.

Cosmetics – Kaolin clay is used as an ingredient in some cosmetic products like facial masks. It helps remove oils and impurities from the skin. The clay also provides a smooth texture.

Medicine – Clays have been used for medicinal purposes since ancient times. Today, certain clays are still used to treat skin conditions, digestive problems, and detoxification. However, effectiveness remains controversial.

Cleaning and polishing – Due to its abrasive nature, clay is used in some cleaning products. It can help scrub surfaces. Clay is also used in metal polishes.

Art supplies – Air-dry polymer clays are used by artists and hobbyists to create jewelry, miniatures, decorative items, etc. These synthetic clays do not require firing.

Gardening – Clay helps improve drainage and aeration in soil. Some clays also introduce important minerals. Clay “pots” slowly release water to plant roots.