This part of EN 13523 specifies the procedure for determining the gloss of an organic coating on a metallic substrate. Gloss is a characteristic of fundamental importance to the appearance of the coil coated product. The apparatus requires a flat specimen of size greater than the aperture, thus, uneven surfaces cannot be measured. This method is applicable to all pigmented and unpigmented coatings including metallic/pearlescent coatings. However, for textured coatings it is only indicative.