Selecting the ideal underglaze is a pivotal step in ceramic artistry, influencing both the aesthetic appeal and durability of your creations. Unlike overglazes, underglazes offer versatility and ease of use, making them particularly suitable for beginners and experienced artists alike. This guide explores essential considerations—from color vibrancy and application techniques to compatibility with clear glazes—to help you make informed choices that elevate your pottery to new artistic heights.
Ease of Use
Underglazes are applied to ceramic bisque and then covered with a clear glaze for decoration. Underglazes are generally less toxic than overglazes and require a lower firing temperature, usually Orton cone 04, which is more suitable for beginners.
When selecting underglazes for your pottery, look for pre-mixed colors that don’t require dilution or mixing before use. This will save you time and ensure consistent results. Also, be sure to select underglazes that are compatible with your chosen clear glaze, as incompatibility can cause crawling or pinholing on the surface of the final piece.
Underglazes can be applied to greenware or clay in the leather-hard stage or to bisque pieces, but are best when used on bone dry ware. This allows the underglaze color to be painted over with a clear glaze and brings out its full beauty. Depending on the type of underglaze, some might require multiple layers to achieve full opacity. However, there are now underglazes available with wide firing ranges that can be used on both low and high-fire clays.
Colors
Underglazes provide students with a great variety of ways to add color and designs to clay pieces before they are sealed with glaze. Whether applied with a slip or an underglaze transfer technique, these colors are incredibly versatile and can yield exciting results even on textured surfaces.
For beginners, pre-mixed underglazes are the most convenient. The jars contain ready-to-use, concentrated, intense, opaque colors that can be used on greenware or bisque.
Pure ceramic stains don’t bond well with clay body surfaces, so underglaze manufacturers dilute them into a recipe of materials – a base medium – that imparts the necessary ceramic properties such as maturity, adhesion, and durability. The mix may contain different percentages of stain, depending on the color: blue stains need higher percentages than orange ones. This is why it’s important to carefully read the label and follow the directions for dilution, dipping, or brushing. A well-mixed underglaze is essential to achieving consistent, uniform results.
Texture
Ceramic artists have a wide range of options for adding color to their clay projects. Among these are glazes and underglazes. Both are used to add color to a fired ceramic piece, but they differ in many ways. These differences impact their chemistry, appearance, intended uses, and firing requirements.
Underglazes feature ceramic pigments suspended in a liquid medium similar to paint. They are applied to greenware or bisque surfaces before covering them with transparent glazes. This allows artists to create designs and patterns that will come up through the overglaze.
Choosing a glaze that is compatible with a particular clay is important to avoid common problems like crawling and pinholing. Performing simple tests in the studio can help determine if the glaze is likely to perform well in your specific firing environment. Using a ceramic glaze testing slurry, ceramicists can see how a commercial glaze behaves in the kiln and identify any issues that may need to be addressed. Finding a reliable ceramic pottery supplier that offers a wide range of glazes and underglazes can simplify this process.
Durability
The role of ceramic glaze is to cover and protect the ceramic body from mechanical damage, but it can also contribute to the aesthetic of a finished product. Choosing underglaze with appropriate color stability, texture, and firing temperatures will help ensure that it meets these goals.
Underglaze colors tend to burn out at higher temperatures, so testing underglazes at the same firing temperature that you’ll be using them with is important. Generally speaking, a low-fire underglaze should fire at around cone 06, while mid or high-fire underglazes can be fired at more than cone 10.
Underglazes are available as liquid underglazes, pencils, crayons, and chalks for use on leather-hard clay or bisque ware. Commercial underglaze lines are available from several manufacturers in a variety of color options.
Enhancing Your Ceramic Creations
Choosing the right ceramic underglaze can significantly enhance the visual impact and durability of your pottery. By considering factors such as color vibrancy, application techniques, and compatibility with clear glazes, you ensure consistent and stunning results in your artistic journey. Whether you’re a beginner exploring the world of ceramics or a seasoned artist refining your techniques, the right underglaze is your partner in bringing your creative vision to life. Explore the possibilities, experiment with different underglaze types, and let your artistic expression flourish on every fired piece.