Color of paper or board

This test is used to measure the color of paper and board by the diffuse reflectance method with spectral gloss elimination as outlined in standards ISO 5631-1 and ISO 5631-2.

The method is not suitable for papers that incorporate fluorescent pigments or colorants. It can, however, be used to determine the color of papers or boards that contain whitening agents, provided that the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C. A fluorescent reference standard that fulfills the requirements of level 3 (IR3) as prescribed by ISO 2469 should be used.