Particle size: optimum particle size to produce maximum opacity is 200–300 nm.

Lithopone’s historical significance is further accentuated by the advancements and modifications that followed its inception. The 1874 patent by J.B. Orr, for instance, ushered in a new white pigment—Orr’s Zinc White. This innovation was attained by co-precipitating zinc sulfate and barium sulfide, followed by a calcination process. Further refinements marked the subsequent decades, the most notable being the enhancement of lightfastness achieved in the 1920s by introducing small amounts of cobalt salts before calcination.

This route affords a product that is 29.4 wt % ZnS and 70.6 wt % BaSO₄. Variations exist, for example, more ZnS-rich materials are produced when zinc chloride is added to the mixture of zinc sulfate and barium sulfide.