ISO 12625-16:2015规定了使用纸背衬通过漫反射测量薄纸或纸巾产品的不透明度的工具测定程序。 ISO 12625-16:2015包含制备单层和多层产品测试件的具体说明，可能需要特殊的准备/程序。 它可以用于确定含有荧光增白剂的薄纸和纸巾产品的不透明度，前提是入射到试片上的辐射的紫外线含量已被调整为符合CIE光源C中使用的荧光参考标准，如ISO 2470-1所述的授权实验室。 ISO 12625-16:2015不适用于含有荧光染料或颜料的彩色纸巾和纸巾产品

ISO 12625-16:2015 specifies the testing procedures for the instrumental determination of the opacity of tissue paper or tissue products by diffuse reflectance using a paper backing. ISO 12625-16:2015 contains specific instructions for the preparation of test pieces of single-ply and multi-ply products, where special preparation/procedures might be necessary. It can be used to determine the opacity of tissue paper and tissue products containing fluorescent whitening agents, provided the UV content of the radiation incident on the test piece has been adjusted to conform to that in the CIE illuminant C using a fluorescent reference standard provided by an authorized laboratory as described in ISO 2470-1. ISO 12625-16:2015 is not applicable to coloured tissue paper and tissue products which incorporate fluorescent dyes or pigments.