Calcium Carbonate Powder (Whiting)

Calcium carbonate (CaCO3), known in ceramics as whiting, is a fine white powder supplied at food grade, typically 98 to 99 percent or better. It is the most widely used source of CaO in glazes, working as a flux in stoneware, porcelain, and mid-range recipes to lower the melt, promote vitrification, and improve durability and chemical resistance.

It also helps keep glaze slurries in suspension and is added to low-fire clay bodies to reduce crazing. Outside the studio it serves as a filler and whitener in paints, plastics, and glass batch, and as a neutralizing agent.