The standard "HG/T 4269-2011 Determination of the distinctness of image release paper for artificial leather" specifies the determination method for the distinctness of image (DOI) of release paper for artificial leather. The standard applies to release paper coated with materials such as polyurethane and polyvinyl chloride (PVC), and its decorative performance is evaluated by measuring the reflection clarity of the film surface on the image. Test instruments include lasers, test benches, imagery screens and optical receivers to ensure accurate measurement of the Optical inspection properties of the release paper.