Calcium being an auxiliary drier, has little drying action in itself but is very useful in combination with active driers.
In vehicles that show poor tolerance for lead, calcium can replace part of the lead with a larger amount of calcium to prevent the precipitation of the lead & maintain drying efficiency. Calcium is often used to replace lead where toxicity of lead must be avoided. Calcium is also useful as pigment wetting & dispersing agents & help to improve hardness & gloss & reduce "Silkins". When ground with drier adsorbing pigments, calcium minimizes loss of dry by being preferentially absorbed.