Lithopone, a white pigment composed of a mixture of zinc sulfide and barium sulfate, has become an indispensable ingredient in the paint industry. Its unique properties, including excellent opacity, high brightness, and resistance to weathering, make it highly valued among paint manufacturers. As the demand for sustainable and efficient paint products grows, the role of lithopone and its suppliers has become more critical than ever.

Although barium sulfate is almost completely inert, zinc sulfide degrades upon exposure to UV light, leading to darkening of the pigment. The severity of this UV reaction is dependent on a combination of two factors; how much zinc sulfide makes up the pigments formulation, and its total accumulated UV exposure. Depending on these factors the pigment itself can vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant may be used, such as a small amount of cobalt salts, which would be added to the formulation. This process creates cobalt-doped zinc sulfide. The cobalt salts help to stabilize zinc sulfide so it will not have as severe a reaction to UV exposure.