Which Clay Is Used For Clay Modelling?
Clay modeling is the process of shaping malleable clay into three-dimensional forms and figures. Artists use various types of clay for modeling based on factors like desired finish, complexity of the sculpture, baking requirements, and more.
The most popular clays for modeling include air-dry clay, polymer clay, earthenware clay, stoneware clay, porcelain clay, and oil-based clay. Each type has distinct characteristics that make them suitable for certain projects over others.
When selecting clay, artists evaluate properties like workability, durability, finishing options, firing requirements, and cost. The ultimate choice depends on the goals of the project, skill level of the artist, and available resources for baking/firing. More advanced modelers may use multiple clay types together in one sculpture.
Air-Dry Clay
Air-dry clay is made of natural clay, water, and cellulose-based binders. Unlike other clays, it air dries naturally and does not require baking. This makes it very easy to work with, so it’s a good choice for beginners. Air-dry clay is available in a wide variety of colors, allowing for creative flexibility.
Since it doesn’t require baking, projects made with air-dry clay dry at room temperature over the course of 24-72 hours. The drying time depends on factors like the thickness of the clay and the humidity in the air. As it dries, air-dry clay hardens while still retaining some flexibility.
One downside is that air-dry clay is not as durable as clays that require baking. Pieces made with it can be more fragile. Air-dry clay also tends to shrink slightly as it dries. But it’s an accessible, user-friendly clay that’s great for crafters of all skill levels.
Polymer Clay
Polymer clay is made from a mixture of polyvinyl chloride, resin, fillers and plasticizers. It remains soft and flexible when stored at room temperature. Polymer clay must be baked in a dedicated oven to harden and cure it. The baking process causes the plastics in the clay to undergo polymerization, forming strong chemical bonds that permanently harden the clay.
Polymer clay is highly malleable and can be shaped into very fine detail. It holds its shape extremely well during sculpting. Polymer clay is available in a wide variety of colors, allowing for colorful and vibrant creations. It can also be mixed to create custom colors. The flexibility of polymer clay makes it popular for crafting miniature figures, jewelry, beads and more.
Earthenware Clay
Earthenware clay is made from natural clay dug from the earth. It is fire-hardened through kiln firing, resulting in a porous, coarser texture. Earthenware clay is one of the most affordable and accessible types of clay. Terracotta, the orange-red clay used for pottery, is a common form of earthenware clay.
Stoneware Clay
Stoneware clay is a natural clay that is fired at high temperatures between 2,200 and 2,400 degrees Fahrenheit. It is less porous and has a finer texture compared to earthenware clay. When wet, stoneware clay is more plastic and stronger than other clays. It is available in various natural colors including grey, brown, buff, and red. Unlike earthenware, stoneware requires firing in a kiln to fully harden it and complete the drying process.
The high firing temperatures make stoneware impervious to water and able to hold liquids without leaking. This makes it ideal for creating kitchenware like mugs, plates, bowls, and other functional items. Stoneware has a smooth semi-vitreous surface and maintains its shape well after firing. It can be left natural or decorated using glazes, stains, or paints. The high clay content gives stoneware increased durability and strength compared to earthenware.
Stoneware is an excellent choice for pottery artists who want to create stained or natural colored pottery with a more refined surface and durability. It can withstand freezing temperatures and abrupt temperature changes. Crazing and cracking are also less likely with stoneware. With its versatility and artisanal look, stoneware clay is commonly used by ceramic artists and sculptors.
Porcelain Clay
Porcelain clay is made from kaolin clay and is one of the most popular clays for modeling and sculpting. It has a very smooth, fine texture that allows artists to capture intricate details in their work. Porcelain clay is fired at the highest temperatures, making it the densest and strongest modeling clay. It has a bright white color when fired and can be translucent in thin areas.
The fine consistency of porcelain clay enables sculpting and shaping of delicate, refined forms. It is an excellent choice for modeling detailed figurines, flowers, animals, and other objects with refined features. Porcelain can be challenging to work with at first due to its firm texture, but becomes more pliable when conditioned with water. It holds its shape very well during drying and firing. With its strength, translucency, and ability to pick up fine details, porcelain clay is a top option for sculptors seeking to create refined porcelain artworks.
Oil-Based Clay
Oil-based clay is made of oils, fillers and waxes. It never fully dries out, so it can be reused repeatedly. Oil-based clay requires no baking or firing to harden. The composition makes it very easy to shape smoothly into forms. However, the range of available colors is more limited compared to other clays. Oil-based clays also do not capture fine details as well as polymer or earthenware clays.
Choosing Clay Type
The type of clay you choose for modeling depends on several factors:
Project and Skill Level – Consider the complexity of your project and your own skill level. Beginners may want to start with an air-dry or polymer clay that is easy to work with. More advanced modelers can handle the challenges of stoneware or porcelain.
Durability vs Workability – There is often a tradeoff between durability and workability. Earthenware clay is very workable but less durable when fired. Stoneware is harder and more durable but trickier to sculpt. Porcelain can be difficult to work with but produces a delicate, translucent finish.
Cost and Accessibility – The cost and availability of clay in your area is a practical consideration. Polymer and air-dry clays are widely accessible and affordable. Earthenware and stoneware may require purchasing from a specialty store or studio.
Safety – Make sure to research the safety considerations of any clay. Some oil-based or polymer clays can emit fumes. Porcelain requires very high kiln temperatures and can be a fire hazard.
Aesthetic Qualities – The different clay types have unique aesthetic qualities. Polymer clays come in bright, saturated colors. Porcelain has a smooth, translucent white finish when fired. Stoneware can create earthy, natural textures.
Consider all these factors when selecting the ideal clay for your next modeling project.
Working with Clay
Once you’ve chosen your clay type, there are some key techniques for working with and sculpting clay. Proper preparation is important for achieving the desired structure and finish.
Kneading, Wedging, Scoring, and Slipping
Kneading clay is critical to ensure any air bubbles are worked out before sculpting begins. It also helps make the clay more uniform. Wedging is a technique for kneading that involves cutting the clay in half, slamming it back together, and repeating. Scoring and slipping refers to scratching the surfaces of two clay pieces and applying water or slip before joining them together. This helps create a stronger bond.
Sculpting Tools
Basic sculpting tools like loop tools, sponge sticks, ribbon tools, and wooden modeling tools allow you to smooth, blend, carve, and create textures in the clay. Metal ribbon tools are good for scraping fine details while sponge sticks can blend for smooth textures.
Finishes
Consider whether you want a smooth or textured look. Smooth finishes take more refining but result in flawless polished clay. Textured finishes can be achieved by imprinting found objects into the clay or using various sculpting tools to create patterns, lines, etc.
Glazing and Painting
For finishing, clay can be glazed and fired in a kiln or painted once dry and set. Glazes come in various colors and finishes from glossy to matte. Acrylic paints work well for hand painting clay sculptures. Allow paint to fully dry before sealing the finished piece.
# Conclusion
When choosing a clay for modeling, the key types to consider are air-dry clay, polymer clay, earthenware clay, stoneware clay, porcelain clay, and oil-based clay. Air-dry clay is easy to use and inexpensive, but fragile when dry. Polymer clay is extremely versatile and durable, but requires baking to harden. Earthenware, stoneware, and porcelain clays are traditional clays that require firing in a kiln, but produce strong, permanent pieces. Oil-based clays offer smooth sculpting and do not require baking or firing, but stay sticky when dry.
For beginners, air-dry or polymer clay are good options to start with since they do not require a kiln. Look for air-dry clays that are non-toxic and claim to harden to a durable finish. For polymer clay, choose a reputable brand like Sculpey or Fimo. Start with basic colors before exploring specialty clays. Practice on simple projects first to get a feel for molding and sculpting with clay.
Clay supplies can be found at local craft stores, art supply stores, and online. Buy clay in bulk for the best value. Gather basic sculpting tools like wire cutters, carving knives, and acrylic roller tools. Use glass or ceramic baking dishes for curing pieces. With the right clay and tools, you’ll be creating unique clay models and sculptures in no time!