Mason Stains

Mason stains can be used to color glazes, slips, and clay bodies. They are fritted to ensure color consistency from batch to batch, though the unfired color may vary. Mason stains can be used at all firing temperatures (but always check the reference number for the stain) but are formulated specifically for use in oxidizing atmospheres. Stains will vary in color, however, depending upon the medium into which they are mixed and firing temperature. 

Using mason stains in clays and slips: For best results, stains should be added to a white clay body or slip base. Fire to normal maturation temperature. Determine the percentage of stain added to the clay or slip by testing. 

Using mason stains in Glazes: Stains can be used to color either transparent or opaque base glazes. Stains are generally added in amounts ranging from 1% to 10% of the glaze batch, measured by dry weight. The higher the percentage of stain, the deeper the fired color will be. The base glaze should contain a calcium carbonate content of 12% to 15% and have no zinc, as zinc can adversely affect colors, especially chromium oxide pinks, vanadium yellows, and cobalt blues. The percentage of stain plus opacifier should equal 15% of the total glaze batch. Remember to always test!