6219 – French GreenMason Stains (by Mason Color Works) are manufactured pigments that can be added to glazes, slips, engobes or even clay bodies. Mason Stains (by Mason Color Works) are more stable than raw oxides carbonates and colors can be achieved that cannot be achieved with raw chemicals. See below for additional information about stains. Q. I purcahsed a color in the past or I see a color on the color chart that is not listed, were some colors discontinued? A. In