The hiding power of organic pigments is also one of the important optical properties of the pigments. When the organic pigments are dispersed in the medium to form the coating film, the opacity of the coating film is completely produced by the pigment. The evaluation of the hiding power of the pigment is actually to evaluate the ability of pigments to cover the bottom material in a coating.

Coating (paint) hiding power is generally expressed as a unit volume or quality coating (paint) can cover the substrate area (Spread rate) (m2 / L or m2 / Kg), in Chinese standards, expressed by the minimum amount of lacquer required for covering unit area . The corresponding paint will be converted into pigment dosage. Pigment covering power is defined as the area that the pigment of the unit mass can cover the base material. It usually represents the minimum amount of pigments that cover the unit area of the bottom material (g/m2).