Ceramic Colorants: Metal Oxides and Pigments
Recipes Sep 12, 2023
In ceramic bodies, i.e. clays and ceramic glazes, color generally comes from oxides. Various metal oxides can give different results under varying conditions. Let’s examine together what ceramic colorants are and how they are used.
Some metal oxides can be harmful to health. Please make sure that you wear a mask and do not consume these materials during use.
What are Ceramic Colorants?
Ceramic colorants; If we had to count them, we could count them as metal oxides (chrome, iron, cobalt, manganese, tin, copper) and pigments.
Metal oxides may give different results depending on glaze types, firing temperatures or kiln atmosphere.
Formulas of Ceramic Colorants
Chromium Oxide -Cr2HE3
Manganese Oxide – MnO₂
Nickel Oxide – NiO
Tin Oxide – SnO₂
Copper Oxide – CuO
Iron Oxide – Fe₂O₃
Cobalt Oxide – CoO
Titan Dioxide – TiO₂
Properties of Ceramic Colorants
Chromium oxide is often used for the green color. In addition, red, yellow, pink and brown are also obtained.
Cobalt is used to give blue tones from light blue to the deepest blue. It can be found as cobalt oxide or cobalt carbonate from raw material suppliers. It gives the color of black ceramic clays. Since cobalt is a hard material, it must be ground well when using the glaze. If there is no possibility of grinding, it would be more practical to use cobalt carbonate.
Copper generally produces green results in oxidation firings, and red results in reduction firings. Like cobalt, copper exists as both oxide and carbonate.
Iron oxide appears as yellow iron oxide, red iron oxide and black iron oxide. There is only a difference in density between them. We can list them as yellow, red and black, from less intense to more intense. Red iron oxide is usually found in the market.
Iron oxide is used in both glazes and mud bodies. The salmon or pinkish color of some muds when baking biscuits is due to the iron they contain.
It produces a wide variety of color tones, from light yellow to red tones to dark brown, depending on the intensity of use in iron glazes or under glazes. It gives metallic results when used above 15%.
Manganese oxide is used to obtain brown tones in glazes and purple and black colors when formulated with other components.
Nickel is often used to tone the colors of other metal oxides.
It is used to create mottled effects and crystals.
It is used in matting glazes and crystal formation.
Pigments are a version of metal oxides treated with different coloring materials. Although it is more expensive than metal oxides, it gives a more noticeable result. There is only one tone difference between the result and the visible color. Pigments are used not only to color glazes, but also to color slips and create underglaze decorations.