What Can I Make Clay?

Clay is a type of fine-grained natural soil material that contains minerals like silica and alumina. It develops plasticity when mixed with water, allowing it to be molded into shapes which retain their form when dried.

Clay has a long history of human use dating back to prehistoric times. Archeologists have found clay figurines and pottery artifacts made as early as 24,000 BC. Clay continues to be an important material for artists and crafters working in ceramics.

There are many different types of clays that vary in their composition, plasticity, firing temperature, and color. Common clays used in pottery include earthenware clays, stoneware clays, and porcelain clays. polymer clays that can be hardened by baking in a regular oven are also popular for arts and crafts.

Gathering Clay

Clay can be gathered from a few different sources. The most traditional method is to dig it straight from the earth. Good clay deposits can often be found near bodies of water or in areas known to have clay soil. Use a shovel to dig down several feet until reaching moist clay beneath the topsoil. Avoid digging clay from contaminated sites or private property without permission.

For a cleaner and easier option, you can purchase clay from craft stores, pottery supply shops, or online retailers. There are many types of clay you can buy pre-packaged and ready to use:

• Earthenware – Fired at lower temperatures, porous and absorbent.
• Stoneware – Denser, fired at higher temperatures to be watertight.
• Porcelain – Very refined and smooth, excellent for detailed sculptures.
• Modeling clay – Oil-based clay that doesn’t require firing.

Consider what type of projects you want to make, as this will determine what kind of clay is best. Earthenware and stoneware clays are good multipurpose options. Porcelain is great for delicate pieces but more challenging to work with. Modeling clay is convenient but won’t hold up over time like fired clay.

Preparing the Clay

Once you have gathered or purchased clay, it requires some processing before you can begin shaping it into pottery or sculptures. Here are some key steps for preparing clay:

Cleaning and Processing Clay

If you dig clay from the ground, it will contain impurities like roots, rocks and debris that need to be removed. Start by breaking up large clumps and allowing the clay to dry slightly. Then pour the clay through a screen or sieve to filter out larger particles. Next, mix the clay with water to a thick, liquid state and pour it through a finer mesh screen. Let it sit so the clay settles to the bottom while the water on top stays murky. Carefully pour off the water and repeat the process until the clay is clean.

Wedging

Wedging is a technique for kneading and working clay to achieve an even consistency and remove air pockets. Start with a lump of clay and cut it in half. Slam and squeeze the halves together, then repeat cutting, slamming and squeezing until the clay feels soft and uniform. Use your palms to apply pressure and work the clay thoroughly. Wedging removes bubbles and makes clay easier to shape.

Kneading

Kneading clay is similar to wedging, but involves folding the clay over itself repeatedly rather than cutting it in half. Knead the clay vigorously with your palms until it reaches the desired consistency. This helps blend moisture throughout the clay and make it more malleable.

Softening Clay

If clay is too firm, there are a few options for softening it. Let the clay soak in water for 10-30 minutes until it absorbs some moisture and becomes more workable. Alternatively, “wedge” in a few drops of water at a time and knead until incorporated. Plastic clay can also be conditioned in a clay extruder to achieve an even, soft consistency.

Removing Air Pockets

Air pockets in clay can cause cracking or exploding during firing. Wedging and kneading are the main techniques for eliminating them. If small pockets remain, pierce them with a pin tool or needle. Avoid using a porcupine tool which can leave rough marks. Take your time with thorough wedging/kneading for smooth clay free of air bubbles.

Shaping Methods

There are several techniques that can be used to shape clay into various forms and figures. The most common handbuilding techniques are pinch pots, coil building, and slab construction.

Pinch Pots: This is one of the most basic and ancient methods for forming clay. Start with a ball of clay and use your fingers and thumbs to pinch and pull the clay upwards to form the walls of a simple pot. Pinch pots are an easy beginner project.

Coil Building: This technique involves rolling out ‘snakes’ or coils of clay and stacking them on top of each other, smoothing each coil into the one below. Coils can be used to build free-standing forms or attached to slabs as decorative elements. Varying the thickness and length of coils creates interesting textures.

Slab Construction: Roll out flat, even slabs of clay and cut shapes using templates. Attach and join slabs by scoring and slipping the surfaces. Slab construction allows for great freedom in building flat planes, geometric shapes, and complex forms.

Wheel Throwing

One of the most common and versatile methods of shaping clay is using a potter’s wheel. This technique requires some initial practice but allows for a high degree of control and consistency when forming round shapes like bowls, cups, vases and more.

The basic process involves several steps:

Centering the Clay

Start by wedging the clay to remove air bubbles and create an even consistency. Form the clay into a ball or cone shape. Place it in the center of the wheel head and apply downward pressure while kicking the wheel to spin slowly. Use your fingers to mold the clay into a symmetrical rounded shape. Stop the wheel and check for any wobble, then recentering as needed until the clay sits firmly without moving.

Opening

With the clay centered, rotate the wheel at a steady speed. Place one or both thumbs into the top center of the clay, pressing down about 1/3 of the way. Gently push outward while applying pressure to form an opening. Widen the mouth evenly while maintaining an even thickness and rounded shape.

Pulling Up Walls

Wet your hands for traction. Place one hand inside the opening while resting the other against the outside wall. Apply gentle outward pressure as the wheel spins to pull the clay upward into an even, vertical shape. Trim any excess clay from the bottom edge using a wire tool. Repeat this process, gradually pulling the wall thinner and higher in controlled movements.

With practice, wheel throwing allows you to shape a wide variety of functional and decorative clay pieces with a smooth surface and refined finish.

Drying the Clay

After you have shaped your clay into the desired form, it’s time to let it dry. Drying the clay properly is a crucial step to prevent cracking and ensure your finished piece holds its shape.

Air drying clay slowly is the best method. Avoid drying clay in direct sunlight or near heating sources like radiators, which can cause uneven drying. Also avoid drying too quickly, which increases chances of cracking and breakage.

To help clay dry evenly, wrap it in plastic wrap or put it in a plastic bag, sealing the edges but not wrapping it tightly. This keeps air moving around the clay while slowing moisture loss.

The drying time depends on factors like clay thickness, environment, etc. Allow at least 24 hours for thin pieces and several days to a week for thicker pieces. Test clay regularly until it is dry to the touch but still cool – this means it is ready for decorating and firing.

With careful, gradual drying, you’ll end up with clay ready to be transformed into a beautiful finished ceramic art piece.

Decorating

Once your clay sculptures are dried and ready to be fired, you have the opportunity to add color, texture, and design through decorating techniques like glazing, painting, adding texture, slip trailing, and incising.

Glazing involves applying a glass-like coating over the clay that melts during firing to create a glossy surface. There are many premixed glazes you can purchase, or you can mix your own custom colors using ceramic glaze recipes. Glazes come in various finishes from matte to shiny. Brushing, dipping, pouring or spraying glaze onto bisqueware are common application techniques.

Acrylic and ceramic paints are another decorating option, allowing you to hand-paint designs in any color onto the clay. Paints can have a matte, satin, or glossy finish. Some specialized paints react during firing to create unique effects like crackling.

You can add visual texture by impressing objects into the clay. Pressing into fabric, lace, leaves, seashells or many other materials will impart their texture when removed. Alternatively, you can use clay shaping tools to scratch lines, dots, or patterns to build texture on the surface.

Slip trailing involves drizzling, pouring or drawing lines of fluid clay slip onto the leather-hard clay surface to create decorative designs. The slip will dry and can be enhanced further with carving or etching tools.

Incising means using sharp tools to scratch lines and patterns into the leather-hard clay. This allows another color of glaze or slip to pool into the recessed lines during firing for dramatic decoration.

Firing

Firing is a critical step in finishing clay projects. Firing hardens the clay through sintering, which fuses the clay particles together at high temperatures. There are several key aspects of firing to understand:

Kilns

Clay must be fired in a high temperature oven known as a kiln. Kilns allow precise control over temperature, heating rate, cooling time, and atmosphere. There are various types of kilns available:

• Electric kilns are common for home use. They use heating elements to generate heat and allow programming of firing profiles.
• Gas kilns use natural gas or propane for fuel. They can reach higher temperatures than electric kilns.
• Wood-fired kilns use wood as fuel. They provide unique atmospheric effects from wood smoke.

Firing Temperatures

Clay must be fired to high temperatures, usually between 1800°F-2200°F, for the sintering process to occur. Specific clay types have defined maturing temperatures. For example, earthenware clays mature around 1800°F-1900°F, while stoneware clays need 2000°F-2200°F. Firing to the proper temperature is critical.

Types of Firings

There are several different types of kiln firings:

• Bisque Firing: An initial low temperature firing that hardens the clay before glazing. Typical bisque temperature is around 1600°F.
• Glaze Firing: The high temperature firing that fuses glaze to bisqueware. Temperatures depend on the clay body and glaze.
• Raku Firing: A specialized technique involving heating vessels in a kiln and then cooling them in the open air. This leads to unique crackled glaze effects.
• Reduction Firing: Limiting air in the kiln to create unique atmospheric effects with certain glazes and clays.

Choosing the right firing method is an important artistic decision based on the desired results.

Final Touches

After firing, clay projects often need some final touches before they are ready for use. Here are some of the most common finishing techniques:

Polishing

Fired clay has a rough, sandy texture. Polishing will create a smooth, glassy finish. Use a fine grit sandpaper or a polishing cloth to gently rub the surface of the clay. Apply polishing cream or wax to achieve an extra glossy shine.

Adding Feet

Items like vases, bowls, and cups may need some feet attached to their base. This prevents them from wobbling and provides ventilation under the piece. To add feet, roll small balls of clay and attach them with slip. Curve the feet so they sit flat on the surface.

Sealing

Applying a sealant will protect the surface of your project and prevent stains. Acrylic varnish and food-safe glazes work well for functional ware like mugs and bowls. Polyurethane makes an effective moisture barrier for decorative pieces used indoors.

Protecting the Finish

Take care not to chip or scratch your finished piece. Store breakable items in felt bags or wrap in soft fabric. Avoid extreme temperature changes. Use coasters, trivets, and table mats. Hand wash only with mild soap and avoid abrasive scouring pads.

Projects to Try

Pottery making can be enjoyed at any level of experience. Clay offers beginners the creative freedom to shape and decorate pieces using their hands, without the complications of paintbrush or sewing needle. Meanwhile, experienced potters can create advanced pieces like fine china using a potter’s wheel or employing sculpting techniques. When beginning, start with functional items that can be used regularly after firing, like cups, bowls, plates, or vases. As skills improve, explore more artistic sculptures.

Some starter projects for beginners:

• Hand-built mugs or bowls using the pinch, coil, or slab methods
• Simple geometric shapes like squares, cylinders, and cones
• Imprinted designs using found objects like shells, leaves, or textured fabrics
• Decorated tiles or plaques using stamps, sponges, or carving tools

More advanced projects for experienced potters:

• Wheel-thrown vases, bottles, bowls, or cups
• Sculptures of animals, people, or abstract shapes
• Relief tiles with detailed textures and images
• Sets of matching dinnerware with consistency in shape, size, and pattern

The possibilities with clay are endless. Be patient, keep practicing your techniques, and let your imagination run wild. Pottery-making is meant to be a fun, relaxing, and creative endeavor for all skill levels.