The ISO 8781-2 standard specifies a method for evaluating the dispersion properties of pigments and extenders through changes in fineness of ground. This standard is applicable to various pigments and extenders and aims to quantify changes in particle fineness during dispersion to evaluate the uniformity of distribution and dispersion efficiency of materials in dispersing media. The test method involves normalizing the sample grinding and using a fineness meter to determine the difference in particle fineness before and after grinding, so as to analyze the dispersion performance of the material. This method provides a scientific basis for the quality control, formulation optimization and performance improvement of pigments and extenders. It is an important technical reference for the pigment industry and related fields.