The ISO 6504-3 "Paints and varnishes - Determination of hiding power - Part 3: Determination of hiding power in building materials, concrete and interior paints" standard specifies the method for measuring Coating hiding power, especially for Coatings used in building materials, concrete and indoor environments. Hiding power is one of the important performances of Coatings, which directly affects the coverage and visual effect of Coatings. The standard details the test equipment, sample preparation, operation procedures and calculation methods to ensure the accuracy and conformity of the measurement results. By implementing this standard, coatings manufacturers and users can better evaluate and compare coatings' ability to cover, ensuring that coatings perform in real-world applications in line with mass requirements.