Oxides
Oxides are chemical compounds formed by the combination of oxygen with metallic elements. In ceramics, oxides play an essential role in creating a wide range of colors in glazes and engobes. Each type of oxide produces a distinctive color when fired at high temperatures in the kiln, and the final result can be influenced by the firing atmosphere, whether oxidizing or reducing. The most common oxides used in ceramics include cobalt oxide, which generates intense blue tones; copper oxide, responsible for deep greens and sometimes metallic colors; and iron oxide, which contributes reds, browns and blacks depending on firing conditions. Other oxides, such as manganese oxide, nickel oxide and titanium oxide, are also used to expand the palette of available colors, allowing experimentation with a wide range of shades and decorative effects.
The interaction of these oxides with the clay and other glaze components is crucial in determining the final color and texture of the ceramic piece. For example, cobalt oxide not only provides a deep blue, but can also influence the translucency and luster of the glaze. Copper oxide, depending on the amount used and the firing atmosphere, can produce everything from bright greens to darker, earthier tones.
In addition to their decorative function, oxides can also influence the physical properties of the glaze, such as its resistance to wear, its impermeability and its adhesion to the clay surface. The correct selection and mixture of oxides is essential to achieve the desired balance between aesthetics and functionality in ceramic pieces.Interesting Fact
In traditional Chinese ceramics, cobalt oxide was considered a highly valuable material because of its ability to produce the iconic blue tones characteristic of Ming ceramics. Cobalt mining and trade were significant economic activities, and control of these sources of cobalt oxide allowed Chinese dynasties to maintain their supremacy in the production of high quality ceramics.Helpful Tip
To obtain consistent and vibrant colors when using oxides in glazes and engobes, it is essential to mix them properly. Be sure to incorporate the oxides evenly into the glaze or engobe base, avoiding the formation of lumps that may affect the quality of the final color. Conduct test firings with small samples to adjust the firing proportions and conditions, ensuring that the resulting color meets your expectations before applying the oxide to large quantities of pieces. Also, keep a detailed record of your mixes and firing times so that you can replicate the desired results in future production runs. Experiment with different oxide combinations and firing atmospheres to discover new shades and decorative effects to enrich your artistic palette.
