JIS K5101-16-1-2004 "Pigment Test Methods, Part 16: water soluble substance. Section 1 Thermal Extraction Method", specifies the technical requirements for the determination of pigment water soluble substance by thermal extraction method. The standard specifies the temperature, time and other key conditions of thermal extraction, standardizes the preparation of the sample, the extraction process, and the separation and quantitative analysis of the water soluble substance. At the same time, it specifies the detection instrument and data processing, providing a unified standard for the scientific determination of water soluble substance content and the evaluation of pigment mass under the conditions of pigment thermal extraction.