The ISO 3233-1 standard specifies a method for the determination of the volume percentage of non-volatile matter in Paints and varnish by the Archimedes principle. This method provides a means of accurately assessing the solid composition of Coatings by measuring the volume percentage of Dry-Film density and non-volatile matter using coated test plates. The standard describes in detail the test procedures, equipment requirements and data processing methods to ensure the Reliability and accuracy of test results. This method is suitable for Coatings research and development, production quality control and product performance evaluation. It can help manufacturers understand the composition of Coatings, optimize formulation design, and ensure the mass and performance of coatings.