The particle size of pigments has long been recognized as important in defining the functionality of coatings systems. Pigment particle size affects the opacity, tinting strength and the undertone associated with a given paint or coating formulation. Here we discuss the use of laser diffraction for measuring the particle size of extenders. The practical relevance of this particle size data is explored with reference to the experience of Viaton Industries, the UK’s largest manufacturer and processor of barium sulphate functional fillers and extenders.
