What Clay Do You Need To Make A Mug?

Making ceramic mugs out of clay is a fun and rewarding hobby for many people. Choosing the right type of clay is an important first step in the mug-making process. The clay you select impacts the look, feel, and durability of the finished mug.

There are several common types of clay used by ceramicists and potters for making mugs. The three main categories are earthenware, stoneware, and porcelain. Each clay has different characteristics in terms of workability, firing temperature, porosity, sturdiness, and appearance.

Selecting the proper clay for your mug project will make the process easier and help ensure you achieve the desired results. Considering factors like the clay’s color, texture, strength, and finishing options will allow you to match the clay to your vision for the finished piece.

With an overview of the most popular clays used for mugs, you’ll be prepared to choose the one that best fits your project goals and style.

Clay Types

There are three main types of clay used for making pottery and ceramics like mugs: earthenware, stoneware, and porcelain. Each type has different properties that affect the look and durability of finished pieces.

Earthenware Clay

Earthenware is a porous, permeable clay that fires at lower temperatures, typically between 1700°F-2100°F. It’s the most commonly used clay for making pottery. Earthenware clay contains high amounts of iron and other impurities that enable the clay to be fired at lower temperatures. When fired, earthenware has an earthy red-brown color from the iron. Earthenware absorbs water, so liquid will seep through an unglazed earthenware mug. For functional pieces like mugs, earthenware clay requires a glaze to make it impermeable to liquids.

Stoneware Clay

Stoneware clay is dense, non-porous, and fires at high temperatures between 2200°F-2400°F. The higher firing temperature causes the clay particles to fully vitrify (fuse), creating a strong, impermeable material. Stoneware clay contains small amounts of iron and feldspar minerals that enable it to form a glassy melt at high fire temperatures. Finished stoneware is non-absorbent and can hold liquids without a glaze coating. However, stoneware mugs are typically glazed to provide an impermeable surface that is easier to clean.

Porcelain Clay

Porcelain is a highly refined, white burning clay. It’s composed mainly of kaolin, a type of clay that fires into a strong, glassy white finish. Porcelain is fired at the highest temperatures, between 2300°F-2600°F. At these temperatures, the clay becomes perfectly non-porous and highly vitrified. Porcelain clay is free of impurities that can cause discoloration. Finished porcelain has a bright white color and resonant bell-like tone when struck. Porcelain is strong, durable, and chip resistant. It can be left unglazed, but porcelain mugs typically have a clear glaze applied.

Earthenware Clay

Earthenware clay is one of the most commonly used clays for making pottery and ceramics. It is characterized by its porous nature and coarser texture compared to other clays. Some key properties of earthenware clay include:

It has a high plasticity and workability which makes it easy to shape and form.
It has a coarse texture due to the presence of non-plastic impurities and inclusions.
It fires at lower temperatures, generally between 1000°F – 2100°F.
After firing, the clay body remains porous allowing water and air to pass through.
It can come in a variety of natural colors like red, buff, brown or gray.

The porous nature and low firing temperature make earthenware clay best suited for making items like flower pots, decorative pieces, tiles and non-food vessels. The key uses for earthenware clay include:

Flower pots, vases, decorative pieces that don’t require water-tightness.
Tiles for flooring, wall cladding and murals because of its coloring and design potential.
Non-food items like vases or vessels since it can absorb water and contaminants.

Earthenware’s absorbent nature and coarse texture limit its utility for cooking ware or liquid storage. But its low firing range and color variability make it ideal for a wide range of decorative and non-culinary items.

Stoneware Clay

Stoneware clay is made from relatively coarse particles that result in a heavier, more durable finished product. The clay tends to be grayish or brownish in color, and works well for items that see extensive daily use. The clay holds its shape well as it dries, allowing potters to create taller, thinner pieces without collapse. After firing at medium-high temperatures of 2100-2300°F (1149-1260°C), the finished product is non-porous and water-resistant.

Stoneware clay is ideal for dishes, cups, mugs, and other functional home goods that need to withstand heat and frequent use and cleaning. The non-porous surface created after firing is perfectly suited for drinking vessels, resisting absorption of liquids or transfer of flavors.

Porcelain Clay

Porcelain clay is highly refined and made up of kaolin, a fine white clay. It is one of the most pristine and strongest clays available. Porcelain clay has the following properties:

Very light in color, usually white or off-white
Extremely fine texture and smooth consistency
Low porosity, does not absorb water easily
Very durable and hardy once fired
Resistant to staining
Fires to a glass-like translucent finish
Withstands repeated cycles in the dishwasher and microwave

Due to its high kaolin content and refined nature, porcelain clay is best used for objects that require thin walls, delicate shaping, and high strength. Some common uses of porcelain clay include:

Fine china tableware like plates, teacups, and saucers
Figurines and decorative pieces
High-end pottery items
Mugs and espresso cups

Porcelain’s durability and translucent white color make it an ideal choice for mugs and other drinkware. The smooth, nonporous surface prevents liquids from being absorbed, while resisting stains and wear. Porcelain mugs can be decorated with glazes and fired to create a beautiful glossy finish.

Choosing Clay for Mugs

When deciding which type of clay to use for making mugs, there are a few key factors to consider:

Durability: How durable does the mug need to be? Earthenware is the least durable clay body, while porcelain is the most durable and resistant to chipping. Stoneware falls somewhere in between. For frequent everyday use, porcelain or stoneware are best.

Heat Resistance: How hot will the liquid inside the mug be? Earthenware can only withstand lower temperatures before cracking, while stoneware and porcelain are safe for boiling liquids. Porcelain is the most heat-resistant.

Color: The different clay bodies have innate colors – earthenware in red, stoneware in grey, porcelain in white. The clay can be stained or glazed to achieve other colors. Porcelain’s white color makes it ideal for a wide range of glaze colors.

For most standard coffee mugs that will go through daily use and need to hold hot beverages, stoneware or porcelain clays are ideal. They provide durability to withstand frequent use and washing, and heat resistance for piping hot drinks. Earthenware is best for more decorative mugs that will be used infrequently.

Working with Clay

Once you’ve chosen the type of clay for your mug, it’s time to start working with it. Here are some key steps in working with clay to make a mug:

Preparing the Clay

Before you can start shaping your mug, you need to prepare the clay. This involves wedging or kneading the clay to remove any air bubbles and make the clay uniform in texture. Start by cutting off a workable amount of clay, then slam it down on your work surface and push it forward with the heel of your hand. Fold the clay over itself and repeat slamming and pushing to blend the clay. This wedging process also helps alignment of the clay particles.

Centering the Clay

Once your clay is wedged, form it into a ball and center it on your pottery wheel. Place both hands around the ball of clay and apply even pressure as you slowly kick the wheel into motion. Keep your hands stable as the wheel turns, allowing the clay to center. Add water as needed to keep the clay from sticking. When properly centered, the clay should rise up evenly into a cone shape.

Throwing the Mug

With the clay centered, you can now start shaping it into a mug. Begin opening up the clay by pushing your thumbs into the center while keeping even pressure with your fingers on the outside. Slowly pull up the walls of the mug, Evening out the thickness as you shape it. Leave an appropriate amount of clay at the base for the mug bottom. Use your tools and water to refine the shape and smooth the walls.

Trimming the Mug

Once the mug has been shaped on the wheel, allow it to become leather hard. Then use a special trimming tool to trim away any excess clay from the base and create a smooth, even bottom. This helps ensure the mug will sit flat and stable. The mug can then be left to dry completely before firing and glazing.

Firing and Glazing

Firing clay is an essential part of the ceramic process. Clay items must be fired in a kiln to harden and set the clay. There are two main firing stages when making ceramic mugs – bisque firing and glaze firing.

Bisque firing is the first firing stage. Items are fired to around 1000°F to harden and prepare the clay body for glazing. Bisque firing removes any water from the clay and makes the piece less porous and absorptive.

After an item has been bisque fired, the next step is to apply glaze and fire again. Glazes are made from finely ground glass, clay, and coloring oxides. When fired, the glaze melts and fuses with the clay body to form a glassy coating.

Glaze firing, also called glost firing, happens at higher temperatures around 2200°F. This causes the glaze to mature and become glass-like. Glaze firing can be done in oxidation or reduction atmospheres, which affects the colors and visual qualities of the finished piece.

There are various types of glazes available for pottery and ceramics:

Glossy glazes have a shiny, glass-like appearance.
Matte glazes have a dull, non-reflective finish.
Crystal glazes contain crystals that burst during firing, creating texture.
Crawling glazes pull back and crackle as they fire.

Choosing the right glaze and glaze firing method brings out the best qualities in handmade ceramic mugs.

Tips and Tricks

When making mugs out of clay, there are some useful tips and tricks to help you avoid common problems and achieve the best results.

Avoid Cracks

Clay can crack during the drying, firing, and glazing process. To reduce cracking:

Allow clay pieces to dry slowly and evenly before firing.
Avoid drastic temperature changes during firing by slowly increasing and decreasing kiln temperatures.
Apply glazes thinly and evenly.
Choose glazes that are compatible with the clay body.
Consider adding grog (ground up fired clay) to stoneware or porcelain to help prevent cracks.

Achieve Uniform Thickness

For even drying and firing, aim for uniform thickness throughout the mug walls and base. The bottom can be slightly thicker for stability.

Smooth Surfaces

Sand surfaces before firing to remove any irregularities. Use a damp sponge after firing to smooth away minor imperfections before glazing.

Test Glazes

Always test glazes on test tiles before applying to completed pieces. Check for proper melt, any reactions with the clay body, and final color.

Clean Work Area

Clay dust can contaminate glazes. Keep your work area clean between sculpting and glazing to prevent defects in the final mug.

Conclusion

When choosing the right clay for making mugs, you’ll want to consider the firing temperature, color, texture, and durability that each type provides. Earthenware is easy to work with and good for handbuilding, while stoneware and porcelain are better for throwing on the wheel. Stoneware provides a strong, watertight mug that works well for both serving hot and cold drinks. Porcelain can make a thin, translucent mug but requires higher firing temperatures. Ultimately, stoneware is likely the best all-around choice for mug making, providing a durable mug that can withstand daily use and dishwasher cleaning. Test out samples of each clay type to decide which you prefer working with and which provides the characteristics you want for your finished mugs.

What Clay Do You Need To Make A Mug?