From a stability standpoint, lithopone, a fusion of zinc sulfide and artificially precipitated barite, is non-toxic and exhibits resilience to mild lyes and acids. However, it is incompatible with colors containing copper. Despite its strong covering power in oil, lithopone’s drying capabilities are notably limited, posing potential issues for artists. Notably, early experimentation with lithopone-based grounds instead of zinc white resulted in undesirable darkening, although this blackness receded upon drying. This unpredictable behavior has sparked debate among scientific communities, emphasizing the need for further exploration and understanding of this pigment.

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 Lithopone B301, Lithopone B311 powder itself may vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant might be used, like 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.