Molding and Shaping: A Guide to the Various Stages of Clay

Table of Contents

The stages of clay include dry clay, slip, plastic clay, leather-hard clay, bone-dry clay, bisqueware, & glazeware. Dry clay is mined and ground into powder. Next, slip is clay mixed with water, plastic clay can be molded. Leather-hard clay is firm but still pliable. Bone-dry is completely dry and hard, bisqueware is fired but not glazed, and finally glazeware is fired and glazed.

Why did the clay break up with the kiln? – Go to the bottom of the page for the answer.

From Raw Material to Finished Product: Exploring the Steps of Working with Clay

Mining, processing, shaping, drying, and firing are the steps in the production of dry clay.

Mining And Processing

Clay extraction and processing: Clay is normally removed from the earth by open-pit mining, and it is subsequently processed into a fine powder.

Clay is extracted from the earth, often by open-pit mining, and processed by being ground into a fine powder. Depending on what it will be used for, different types of clay are mined. Different kinds of clay are utilized in various ways and have varying qualities. For instance, bentonite clay is used in drilling mud and the cleanup of industrial waste, whereas kaolin clay is frequently utilized in the manufacture of paper and ceramics.

The layers of soil and rock that are above the clay deposit—the topsoil and overburden—are often removed during the mining operation. Heavy equipment like bulldozers and excavators are used for this. The exposed clay is then recovered, moved to a processing plant, crushed, and processed into a fine powder.

After that, the powder is screened to get rid of any impurities like pebbles and trash and to make sure the clay particles are the right size. The clean clay powder is subsequently prepared for usage in a range of commercial and industrial applications, including ceramics, bricks, and building supplies.


Powder is combined with water to make a pliable substance that can be molded into different shapes using methods including hand building, molding, press molding, and pottery wheel.

In the stage of clay processing known as “forming,” water is combined with clay powder to create a pliable substance that can be molded into a variety of shapes. Hand building, pottery wheel throwing, press molding, slip casting, and jiggering are some of the techniques used to make clay.

Hand Building

In this technique, the clay is shaped by hand using implements like knives, ribbons, and fingers. This technique is frequently applied to produce larger, more sculptural forms.

Without the use of a pottery wheel, hand building is the process of manually sculpting clay. It is a flexible technique that enables the creation of a variety of forms and shapes.

Pottery frequently employs a variety of hand construction methods, including:

Coil building: Rolling out long, thin coils of clay and stacking them to make the shape you want is known as coil construction. To make a seamless object, the coils can be linked and smoothed. Large, sculptural forms are frequently produced with this technique.

Slab building: In this method, flat clay slabs are rolled out and shaped by draping or molding them over a form. From functional pottery to artistic works, slab building can be utilized to create a broad variety of forms.

Pinching: Using your thumb and fingers to pinch the clay, you may mould it into whatever shape you like. It is frequently used to make tiny, intricate objects like beads and figurines.

Molding: Using a pre-made mold to form the clay is known as molding. To manufacture an identical item, clay is squeezed into the mold and then removed. This technique is frequently used to make multiples of a single piece or to make a particular shape that is challenging to make by hand.

Extruding: This method entails forcing clay through an apparatus known as an extruder, which forms the clay into a certain shape, like a tube or rope. Functional pottery and architectural ceramics are frequently made using this technique.

Why I Like Hand Building?

Because the potter has complete control over the piece’s shape, size, and features when hand constructing, allowing for a wide spectrum of inventiveness. Hand building produces items that are frequently more sculptural in form and are not only restricted to the conventional bowl and cylinder shapes produced on a wheel.

Pottery Wheel Throwing

Clay is molded by hand into symmetrical shapes like bowls, cups, and vases using the pottery wheel, which is a rotating platform.

Throwing clay on a pottery wheel, sometimes referred to as a potter’s wheel, is a method of molding clay. It is a method that makes it possible to create symmetrical, exact objects like bowls, vases, and cups. A lump of clay is spun rapidly on a pottery wheel, allowing the potter to mold the clay with their hands while it rotates.

The clay is centered on the wheel head to start the wheel throwing procedure. The potter applies pressure, pulls, and shapes the clay as it spins using their hands and tools to create a symmetrical form. The clay can be shaped by the potter by cutting a hole in the middle, making a hollow form, or pushing up the sides to make a taller form. The potter will cut off any extra clay once the required form has been obtained and then add any final embellishments, like a handle or spout.

Before removing the object from the wheel head, the potter gives it a brief period of drying. Prior to being fired in the kiln, the object is then allowed to dry even more. The sculpture can be glazed and fired once more, depending on the kind of clay and the desired outcome.

Wheel throwing is a skill that takes practice, patience, and skill to master. It enables the construction of exact and symmetrical forms that are challenging to accomplish through hand building. From useful pottery to sculptural pieces, the potter can produce a broad variety of forms, and the process can be very meditative.

Press Molding

Clay is shaped using the press molding technique, which includes pressing it into a mold composed of metal, plaster, or another material. The process of creating recurring, identical forms is frequently employed.

Clay is shaped using a pre-made mold in the pottery press molding process. Plaster, wood, or metal are just a few of the materials that can be used to create a mold. Press molding starts with the creation of a mold in the required shape, frequently utilizing a master model or prototype. To stop the clay from clinging to the mold after it has been created, a release agent, such as talc or wax, is applied to the mold.

The clay is then shaped and any air bubbles are removed by pressing a ball of clay into the mold using a device called a rib. The clay is then taken out of the mold, and any extra is cut off. The object is then removed from the mold after a brief period of drying. By hand, the artwork can be further honed and detailed.

Multiple identical components can be produced rapidly and effectively using the press molding technique. It is frequently employed to produce several copies of a single item or to produce a particular shape that is challenging to obtain through hand or wheel throwing. For the large production of utilitarian pottery like tiles, bricks, and plates, press molding is very helpful.

Slip Casting

In this technique, liquid clay, or “slip,” is poured into a plaster mold, which absorbs the water from the slip and leaves the clay in the mold’s shape. Multiple copies of the same form are frequently created using this technique.

Clay is shaped using a liquid clay mixture called slip in the pottery slip casting technique. Clay, water, and a deflocculant are the ingredients in slip, which helps to keep the clay particles suspended in the water. Making a plaster mold of the desired shape is the first step in the slip casting process, which frequently makes use of a master model or prototype. To stop the clay from clinging to the mold after it has been created, a release agent, such as talc or wax, is applied to the mold.

After that, a thin layer of clay is left inside the mold after the slip has been poured into it and allowed to sit for a period of time, often a few minutes. The object is then removed from the mold after a brief period of drying. The item can be hand-finished and more detailed, or it can be glazed and fired in a kiln.

Using the slip casting method, numerous identical pieces can be produced fast and effectively. It is frequently employed to produce several copies of a single item or to produce a particular shape that is challenging to obtain through hand or wheel throwing. Slip casting is also effective for producing mass-produced, utilitarian pottery such as tiles, bricks, and plates.

How Is Liquid Clay Different Than Ball Clays Or Bone Dry Clays In Terms Of Its Properties?

Slip, commonly referred to as liquid clay, is a suspension of clay particles in water. It differs from ball clays and bone dry clays in a number of ways, including:

  • In terms of consistency, ball clays and bone dry clays are solids, whereas liquid clay is a liquid. Ball clays and bone dry clays need to be mixed with water before usage, whereas liquid clay can be poured or brushed on.
  • Plasticity: Compared to ball clays and bone dry clays, liquid clay is less flexible. When used to make pottery, it loses some of its fine detail and razor-sharp edges.
  • Shrinkage: Compared to ball clays and bone dry clays, liquid clay shrinks more quickly. As a result, pottery constructed of liquid clay will shrink more during firing, which may result in breaking or warping.
  • Porosity: Compared to ball clays and bone dry clays, liquid clay is more porous. In comparison to pottery manufactured with ball clays or bone dry clays, pottery made with liquid clay will absorb more water and be more fragile.
  • Color: Ball clays and bone dry clays can have a variety of hues based on the mineral content of the clay, although liquid clay is often gray or white in color.
  • Impurities: Compared to ball clays or bone dry clays, liquid clay is more likely to include impurities, which could change how the work turns out.
  • Additions: Unlike ball clays or bone dry clays, liquid clay is not prepared with additives like grog or feldspar, which might change the final characteristics of the pottery.

Slip Clay And Native American Potters (Interesting Facts And Techniques)

Slip clay, commonly referred to as liquid clay, is crucial to Native American potters’ pottery production. In order to give pottery a smooth, even surface and to add decorative elements, slip, a liquid clay and water mixture, is put to the surface.

Slip is frequently utilized to make elaborate patterns and decorations in Native American pottery. A brush is used to apply the slip to the pottery’s surface, and a tool is then used to scratch or carve the design into the surface. The pottery is then decorated with mineral pigments after the slip has been fired.

The coil-and-scrape technique for making pottery also employs slip. In this technique, the potter coils the clay to form the pot, then smooths the surface with a scraper. Slip is frequently applied to the pot’s surface to give it a smooth finish.

In the firing of Native American pottery, slip is also crucial. In addition to helping to create a smooth surface on the pottery, the slip also aids in protecting it during firing.

In conclusion, Native American potters employ slip clay as a decorative component, surface finish, and protective coating throughout the firing process. Slip is a flexible substance that may be applied to pottery in a variety of ways to improve its aesthetic appeal and practicality.

How Have Native American Potters Mastered The Use Of Liquid Clays To Create Beautiful Pieces Of Art Throughout History?

Liquid clays, also known as slip, have been used by Native American potters for a very long time to produce stunning works of art. By creating methods to regulate the slip’s flow, consistency, and thickness as well as how it is applied to the pottery, they have mastered the use of liquid clays.

Coil-And-Scrape Method

The coil-and-scrape method is a typical method used by Native American potters. Clay coils are added to the pot to increase its height, and the surface is then smoothed using a scraping instrument. Before smoothing, the slip is placed to the pot’s surface, aiding in the creation of an even and smooth surface.


Another method is known as Sgraffito, and it entails making designs by scratching through a layer of slip to expose the underlying clay. This makes it possible to decorate the pot’s surface with elaborate patterns and decorations.

Slip Decoration

Slip decoration, where the slip is put on the pot in a specific pattern or design, is another technique used by Native American potters. After that, the slip takes on a color distinct from the clay body of the pot and is fired. For pottery like Mimbres pottery, this method is frequently utilized because it produces a lovely contrast between the two hues.

The Technique Of Inlaying

Native American potters also employ the method of inlaying, in which various colored slips are put to the surface of the pot and then chiseled away to produce elaborate designs. They also utilize molds to create certain shapes.

Overall, Native American potters have developed a number of techniques and methods to use liquid clays, which has enabled them to produce stunning and complicated works of art throughout history.


This technique entails pressing clay against a revolving plaster mold using a jigger tool to shape it. To produce uniform, identical forms, this technique is frequently utilized in the production of industrial ceramics.

Using a mechanical jiggering equipment, pottery jiggering involves molding clay. The jiggering machine is a specialized equipment that molds clay into exact, symmetrical shapes using a rotating mold and a flexible tool known as a jigger arm.

Jiggering begins with the construction of a plaster cast in the required shape. The clay is poured over the mold after it has been set in the jiggering machine. The clay is precisely shaped to fit the mold’s curves as the jigger arm glides over the mold’s surface. You may also add elements like handles and spouts with the jigger arm.

When the object is finished being formed, the mold is removed, and any extra clay is cut away. The object is then removed from the mold after a brief period of drying. The item can be hand-finished and more detailed, or it can be glazed and fired in a kiln.

Jiggering is a method that makes it simple and rapid to produce numerous identical components. It is frequently employed to produce several copies of a single item or to produce a particular shape that is challenging to obtain through hand or wheel throwing. Jiggering is also excellent for producing practical pottery in large quantities, such as plates, bowls, and cups.


Greenware is the term used to describe the stage after the clay has been created before it can be fired. Depending on the thickness of the item and the ambient humidity, the drying process can take a few days to a few weeks.


Drying: The clay must dry out after forming in order to be fired without cracking.

Because it enables the clay to dry out slowly and uniformly, which is essential for minimizing cracking during firing, drying is a critical step in the clay’s formation process. The clay may fracture or distort if it dries too rapidly or unevenly, causing the outside to dry more quickly than the interior.

Clay pieces that have been shaped and are ready to be fired but have not yet been cured are referred to as “greenware” during the drying process. Depending on the thickness of the item and the ambient humidity, the drying process can take a few days to a few weeks.

The clay will shrink as it dries out because it loses water. The type of clay and the ambient humidity both affect how quickly things shrink. While clay that shrinks too slowly can twist, clay that shrinks too quickly can crack. Potters frequently use plastic bags or wrap the pieces with moist cloths to halt the process of shrinkage.

Because it is entirely dry, hard, and prepared to be fired, the clay is referred to as “bone dry” after drying. The process of firing involves heating clay to a high temperature in a kiln, which results in chemical and physical changes that strengthen and increase its durability.

Before firing, the clay must be entirely dry; otherwise, the water trapped inside the clay would cause it to rupture or explode inside the kiln. Additionally, it’s critical to have strong control over the drying process because it can change the size, shape, and color of the finished product.

What Is The Leather Hard Clay Stage, And How Does It Affect The Ceramic Process?

The ceramic process has reached the leather hard clay stage, at which the clay is stiff but yet malleable enough to be handled and further moulded. After the clay has been hand-built and given enough time to cure, or after it has been thrown on the wheel, this step normally takes place.

The clay is still pliable when it reaches the leather hard stage, allowing for further manipulation and work. In addition to trimming and adjusting the pot’s form, potters can add embellishments and ornamentation. Additionally, they can add handles and spouts and do any required repairs.

The item can be let to dry more once it reaches the leather-hard stage, but the potter must watch out that it doesn’t dry too rapidly because this might lead to cracking. A pottery piece may bend or crack if it is allowed to dry out too quickly. The item could lose its shape if too much water is added at this point, therefore potters must be careful not to overdo it.

The pottery can be bisque fired when it has dried. Bisque firing is a low-temperature firing technique in which the clay object is fired until it hardens but is not yet vitrified. The item can become more sturdy and long-lasting after this firing, and the clay’s shrinkage during the final firing can also be reduced.

How Do Changes In Moisture Content Affect Bone Dry Clay Behavior During Firing?

Changes in moisture content can have a significant impact on bone dry clay’s behavior during firing. If the clay has too much moisture, it can cause cracking and warping as the water expands and evaporates during the firing process. On the other hand, if the clay is too dry, it can cause shrinkage and cracking as the clay loses moisture. In addition, the rate of heating and cooling can also affect the final result, with rapid heating and cooling causing more stress on the clay and potentially leading to more cracking and warping. Overall, it is important to carefully control the moisture content and heating and cooling rate of bone dry clay to achieve the desired results during firing.


Firing: In a kiln, the clay is heated to a high temperature, causing chemical and physical changes that increase its strength and durability. The firing temperature and length will change depending on the kind of clay used and the ultimate product sought.

Clay is strengthened and made more robust through the firing process, which involves heating it to a high temperature in a kiln. Electric kilns, gas kilns, wood-fired kilns, and salt/soda kilns are only a few examples of the various kiln types used for firing clay. The final product that is intended as well as the type of clay being utilized determine the type of kiln that is used.

Several steps are followed by the clay during firing:

  • Dehydration: The clay shrinks as the residual water is lost.
  • The clay is heated to a lower temperature, usually between 900 and 1100 °C, during the bisque firing process. This allows the clay particles to bind together and form a hard, vitrified object. Bisque firing is another name for this phase.
  • Some sculptures go through a glaze firing, which involves applying a coating of glass to the clay’s surface. The glaze is then fired at a higher temperature, often between 1200 and 1300 °C, causing it to melt and fuse to the clay’s surface, giving the surface a smooth and glossy finish.
  • Reduction firing is a unique firing technique that involves changing the kiln’s atmosphere to create a reduction environment, which allows the clay to change color and form new surface patterns.
  • Oxidation firing is the reverse of reduction firing, in which the kiln’s atmosphere is changed to create an oxidation environment, which causes the clay to change color and form new surface patterns.

The type of clay, firing temperature, and firing time will all affect the finished product. Although it may be more brittle, clay that has been fired at high temperatures is stronger and more resilient. The firing circumstances, including the kind of kiln used and the atmosphere inside the kiln, will also affect the final color and texture.

What Are The Types Of Clays Used In Pottery?

Clay is made from a variety of sources, each with special qualities and applications in pottery.

Fine-Grained Clays

Clays with fine-grained structure feature tiny, closely packed particles that give them a smooth, fine texture. They are frequently used to make delicate, intricate items like figurines and teacups. Clays with fine grains include kaolin, ball clay, and porcelain, to name a few.

Earthenware Clays

Clays used in earthenware pottery contain larger, more porous particles and a rougher texture. Typically, they are used to make thicker, more practical pieces like plates, bowls, and jars. Pottery for everyday usage is frequently made with earthenware clay. In comparison to other clays, they are usually fired at lower temperatures.

Stoneware Clays

Clays used in stoneware have a medium texture and are fired at temperatures greater than those used in earthenware. Typically, they are used to make thicker, more practical items like mugs, vases, and casseroles. Since they are not porous, they are sturdy and long-lasting and can hold liquids.

Porcelain Clays

Clays used to create porcelain figurines, exquisite china, and other delicate items are known as porcelain clays. They are usually fired at extremely high temperatures, producing a dense, hard substance.

Heavy Clays

Larger, more sculptural works like planters and outdoor sculptures are frequently made from heavy clays. They are better suited for large-scale work since they are denser and heavier than other clays. They are frequently employed for bricks, tiles, and architectural ceramics.

It is possible to combine different kinds of clay to create a new substance with certain qualities that are suitable for the intended final result. To alter the clay’s characteristics, a potter might also add additional elements like grog (fired clay that has been ground up), sand, or fibers.

What Are The Different Types Of Pottery That Are Made From Clay?

Did you know from straightforward utilitarian jars to elaborate sculptures, clay can be used to create a wide variety of pottery? Several that come to mind:

Functional Pottery

Dishes, cups, bowls, and vases are examples of functional pottery. These items, which might take on plain, unadorned forms or more decorative ones, are frequently created to be used in daily life.

Sculptural Pottery

Sculptural pottery: Instead of being used for practical purposes, sculpture pottery is created as a beautiful or artistic piece. Figurines, statues, and abstract shapes are all examples of sculptured pottery.

Raku Pottery

Raku pottery is fired at a lower temperature than traditional pottery and is frequently taken out of the kiln while still hot. This method produces a distinctive cracked glaze and can be applied to both practical and sculptural objects.

Majolica Pottery

Majolica pottery is made of brilliantly colored, thick glazes. It is frequently included into the creation of decorative items like plates and vases, and it frequently features elaborate designs and themes.

Stoneware Pottery

Stoneware pottery is a type of pottery that is fired at a high temperature, often between 1200 and 1300 degrees Celsius. It is a tough, sturdy, and long-lasting pottery that is frequently used for practical items like cookware and storage containers.

Porcelain pottery: Kaolin clay, feldspar, and quartz are used to make porcelain, a form of pottery. At a very high elevation, it is fired.

How To Choose The Right Clay For Your Pottery Project

The sort of pot you want to build and the desired finish are just two of the many factors to take into account when selecting the best clay for your pottery project. Here are my top suggestions to aid you in making your decision:

  1. Think about the kind of pot you want to create: Plasticity, shrinkage, and firing temperature are just a few of the characteristics that differentiate clays. A heavy clay is better suitable for larger, more utilitarian sculptures, whereas a fine-grained clay is better suited for delicate pieces like figurines.
  2. When fired, various clays can produce a variety of finishes, so take that into account. When fired, for instance, a red clay will produce a red-orange tint, whereas a white clay will produce white or off-white. Additionally, some clays result in a glossy finish, while others in a matte finish.
  3. When choosing a clay, it’s crucial to take the firing temperature into account. Some clays are better suited for high-temperature firing than others, and different clays have varying firing temperatures.
  4. Think about the accessibility: You can have more or less alternatives for clays to choose from depending on where you live. Knowing what is offered and how much it costs in your area is crucial.
  5. Attempt before you buy: It is preferable to experiment with a tiny amount of clay first to observe how it reacts to the shaping, drying, and firing processes before committing to a larger amount.
  6. If you’re unclear about the best clay to use, don’t be afraid to approach more seasoned potters or a pottery supply store for guidance. They’ll be able to direct you and aid in your search for the ideal clay for your undertaking.

Tips For A Successful Pottery Project

From selecting the best clay to selecting the best firing technique, there are various steps to a successful pottery production. To assist you produce a successful pottery project, here are my most valuable pointers:

Pick the right clay: As was already noted, various clays have distinct qualities and are better suited for certain finishes and pot types. Considering the type of pot you want to build, the desired finish, and the firing temperature are all key factors when choosing the clay for your project.

Test your clay: It’s a good idea to test a small bit of clay first to see how it performs during the forming, drying, and firing processes before committing to a significant amount.

Plan your project: Spend some time outlining your project before you begin. Make measurements, sketch out your design, and think about the technical details of your project, such warping and shrinking.

Practice your techniques: Whether you’re creating your pot by hand or on a wheel, you should practice your techniques to improve your abilities and produce a better completed product.

Take care in the drying process: Drying your pottery properly is essential to preventing cracking, so take care during the process. Keep your pottery away from drafts and direct sunlight as it dries gently and evenly.

Pick the appropriate firing technique: Since different firing techniques yield varied results, it’s critical to select the appropriate firing technique for your project. For instance, high-temperature firing results in a tougher, more durable pot, but raku firing results in a distinctive cracked glaze.

Be patient: It takes time, perseverance, and practice to make pottery. If your initial efforts don’t go exactly as you had hoped, don’t give up. Continue to explore and gain knowledge.

How To Store And Display Your Pottery

Your pottery pieces will last longer and look better if they are stored and displayed correctly. The following advice will help you store and exhibit your pottery:

Keep pottery dry and away from moisture: Pottery should be kept in a dry environment. This will lessen the chance of warping and cracking.

Wrap your pottery in acid-free tissue paper or bubble wrap before storing to avoid scratches and damage.

Use a pottery stand to keep your pottery sturdy and straight and stop it from toppling over.

Display in a Well-Lit Area: Pottery looks best when presented in a space with good lighting so that the colors and textures can be appreciated.

Consider utilizing a display container to shield your pottery from airborne contaminants and other environmental influences.

Keep pottery out of the sun: Over time, exposure to direct sunlight can fade and discolor pottery.

Rotate your collection: Rotate your collection on a regular basis to avoid damage and to make sure that all of your pottery is visible and appreciated.

Maintaining and cleaning your pottery on a regular basis will make it appear its best. Avoid using abrasive cleaners on your pottery since they could scratch the surface.

Are There Commercially Available Clay Bodies That Can Be Used For Pottery?

There are clay bodies that may be purchased commercially and used to make pottery. These clays are designed to have particular characteristics that make them suitable for various forms of pottery, such as shrinkage, plasticity, and firing temperature. The following are some of the most typical kinds of clay bodies that are offered commercially:

Earthenware: Earthenware is a low-fire clay that is normally fired between 1,800 and 2,200 degrees Fahrenheit. Because it is porous, the clay is frequently coated to make it waterproof.

Stoneware: Stoneware is a mid-fire clay that is fired between 2,200 and 2,400 degrees Fahrenheit. It is a hard, non-porous clay that is frequently used to make practical pottery like bowls and mugs.

Porcelain: Porcelain is a high-fire porcelain clay that is fired between 2,400 and 2,600 degrees Fahrenheit. It is a highly refined, extremely fine-grained clay that is frequently used for delicate, beautiful pottery.

Raku: Low-fire Raku clay is typically fired between 1,800 and 1,900 degrees Fahrenheit. It is frequently used for decorative pottery and is renowned for its distinct cracked glaze.

Sculpting Clays: Clays designed specifically for sculpture have a high degree of flexibility and are simple to shape. Depending on the formula, they can be fired at various temperatures.

How Does Pottery Clay Differ From Other Types Of Clay?

Clay specifically designed for making pottery, a kind of ceramic art, is known as pottery clay. There are various ways that pottery clay is different from other forms of clay:

Plasticity: The ability of pottery clay to be molded and moulded is determined by its formulation. Not too soft or too stiff, pottery clay should be simple to work with.

Shrinkage: When pottery clay is fired, it will shrink. A certain shrinkage rate, or percentage of shrinkage that happens during firing, is included into the formulation of pottery clay.

Temperature of firing: Pottery clay is designed to be fired within a certain temperature range. For instance, compared to stoneware or porcelain, earthenware clay is often fired at lower temperatures.

Porosity: The porosity of pottery clay varies, which refers to the clay’s capacity to permit water to travel through it. Compared to stoneware or porcelain, earthenware is more permeable.

Color: Depending on the mineral makeup of the clay, pottery clay can be a variety of hues. While some clays are white, gray, or black by nature, others are naturally red.

Impurities: In order to have consistent behavior during the firing process, pottery clay is treated and cleaned of impurities. Some varieties of clay are sold already refined, while others require the potter to refine them.

Additives: To improve particular attributes like strength and thermal expansion, pottery clay can be produced with a variety of additives, including grog (crushed fired clay), feldspar, and silica.

Unlike other varieties of clay like modeling clay, sculpting clay, and potter’s clay, pottery clay is a specialized sort of clay that is produced to fit the unique needs of pottery manufacture.

Are There Any Unique Benefits To Using Ball Clays Over Other Types Of Commercial Clays When Creating Ceramics?

Yes, utilizing ball clays instead of other commercial clays when making ceramics has a number of special advantages.

Ball clays are renowned for having a high degree of flexibility, making them simple to work with and capable of taking on a wide range of shapes. They are therefore perfect for producing elaborate or finely detailed sculptures.

Additionally, they have extremely little shrinkage during the firing process, which lessens the likelihood of the finished object cracking or warping.

Ball clays are good for manufacturing glossier and more transparent glazes because of their tiny particle size, which produces a smooth surface finish.

The great degree of whiteness that ball clays are known for can be advantageous when producing extremely white ceramics.

In order to prevent settling and increase the uniformity of glaze application, they are also effective at suspending and suspending glazes.

Ball clays are generally a preferred choice among ceramicists and potters because of their positive qualities like plasticity, low shrinkage, and tiny particle size.

Popular Ball Clays

Potters employ a variety of well-known ball clay brands. Here are a few:

Kentucky OM4: This ball clay is popular among potters for throwing and hand-building due to its excellent plasticity, tiny particle size, and low shrinkage rate.

EPK (Kona F4): This ball clay, which is frequently used to make excellent porcelain and bone china, is also renowned for its great plasticity and tiny particle size.

Old Hickory: A polymeric kaolin-based ball clay with exceptional throwing characteristics and tiny particle size is known as Old Hickory.

Tennessee B3 Ball Clay: Tennessee B3 Ball Clay is a multipurpose ball clay that works well for casting, modeling, and throwing. It is highly plastic, has tiny particles, and shrinks very little.

Darley Dale: It is a ball clay, very comparable to OM4, suited for throwing and modeling, with great plasticity, tiny particle size, and minimal shrinkage.

FAQ: The Stages of Clay

What are the 7 stages of clay?

The 7 stages of clay are as follows:

  1. Slip: Liquid clay used in casting and decoration.
  2. Plastic: Soft, workable stage ideal for molding and shaping.
  3. Leather-hard: Partially dried but still pliable; perfect for carving or adding details.
  4. Bone-dry: Completely air-dried but not yet fired; extremely fragile.
  5. Bisque: The first firing stage, making the clay item more durable but still porous.
  6. Glaze: The stage after applying glaze but before the final firing.
  7. Vitrification: Final firing stage, where the clay becomes a mature, non-porous ceramic.

What are the stages of clay activities?

The stages of clay activities generally follow the stages of clay, starting with:

  1. Wedge and Prepare: Knead the clay to remove air bubbles and prepare it for work.
  2. Shape: Use various techniques like pinching, coiling, or wheel-throwing to form your piece.
  3. Add Details: When the clay is leather-hard, add handles, carve designs, or attach additional pieces.
  4. Dry: Allow the piece to reach the bone-dry stage.
  5. First Firing (Bisque Firing): Fire the piece in a kiln to bisque stage.
  6. Glaze: Apply glaze to the bisqueware.
  7. Second Firing (Glaze Firing): Fire the piece again to melt the glaze and complete the ceramic process.

How long does it take for clay to go through each stage?

The time it takes for clay to go through each stage can vary widely depending on factors like humidity, thickness of the clay, and the specific type of clay used. However, general guidelines are:

  • Slip to Plastic: Immediate
  • Plastic to Leather-hard: Few hours to a day
  • Leather-hard to Bone-dry: 1-3 days
  • Bone-dry to Bisque: Several hours in a kiln
  • Bisque to Glaze: Varies depending on glaze drying time
  • Glaze to Vitrification: Several hours in a kiln

Can I speed up the drying process?

While it’s possible to speed up the drying process using fans or heat lamps, doing so can lead to cracks or warping in the clay. It’s generally best to let clay dry naturally to preserve its integrity.

What happens if I skip the bisque firing stage?

Skipping the bisque firing and going straight to glaze firing is known as “once-firing.” This can be risky because the clay is more fragile and susceptible to cracking. Bisque firing also makes the clay more porous, making it easier to apply glazes evenly.

How do I know when my clay is ready for glazing?

Your clay is ready for glazing once it has gone through the bisque firing stage. It will be more durable, lighter in color, and will have a porous texture that can readily absorb glazes.

Are there types of clay that don’t need to go through all these stages?

Yes, there are types of specialty clay like air-dry clay or oven-bake clay that don’t require kiln firing. However, these types of clay are generally not as durable as traditional ceramic clay that goes through the kiln-firing process.

Why did the clay break up with the kiln?

Because it felt like the relationship was always “heating up” too fast!

Bonus joke because you red this far! Why did the clay get kicked out of school?

Because it couldn’t keep its “composure” during the bisque firing!


Rice, P. M. (2015). Pottery analysis: a sourcebook. University of Chicago press.

Rice, P. M. (1999). On the origins of pottery. Journal of archaeological method and theory, 6, 1-54.

Jones, R. F. J. (1979). Why pottery. Pottery and the Archaeologist, 1-5.

Skibo, J., Skibo, J. M., & Feinman, G. (Eds.). (1999). Pottery and people. University of Utah Press.

Orton, C., Hughes, M., & Hughes, M. (2013). Pottery in archaeology. Cambridge University Press.

Timby, J. (2000). The pottery. Rippon 2000a, 174-83.

Skibo, J. M. (1992). Pottery function: a use-alteration perspective. Springer Science & Business Media.

By Mike White, CC BY-SA 2.0,

By Poupou l’quourouce – Own work, CC BY 3.0,

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