GB/T 21782.12-2010 "Powder coatings – Part 12: Determination of compatibility" specifies the test method for evaluating the deterioration of surface properties of coatings due to compatibility issues when two different powder coatings are mixed. The results depend on the chemical reactivity, chemical composition, and fusibility of the coatings. Compatibility is determined by observing whether the mixed coating exhibits surface defects such as changes in gloss, pinholes, or orange peel. The test requires specialized spraying equipment for powder coatings, curing ovens, and other instruments, providing a technical standard for assessing the mixing suitability in the production and application of coatings.