A very versatile stain which disperses well through a glaze, normally producing a green colour but giving reds and yellows in lead glazes, and pink in the presence of tin.
Chrome oxide can be used as a body stain in amounts to 5% to give grey-green, up to 3% in glaze recipes. Drab chrome greens can be moved toward peacock green with the addition of cobalt oxide (1% each gives bright color). This works in boron and soda glazes. Chrome in zinc glazes tends to form brown zinc chromate.
Because chrome reacts with normally inert tin to produce chrome-tin pink colors whiting and alumina are usually used instead of tin to lighten and clarify chrome green glazes. Chrome-tin pinks are much more consistent if the combination is premelted (i.e. commercial stain) and if the glaze is high in calcium or strontium, and free of zinc. Strontium is most effective if a wide firing range is desired (0.1-0.5% chrome, 4-10% tin).
Chromium oxide is added to enamels for green where borax and zinc are used to increase the brilliance of the colour. However, chrome in ground coat enamels tends to react with the metal to cause blistering.
Zircon opacifier 1-2% is often added to chrome glazes to stabilize them and prevent brown edges.