ISO 787‑15 is part 15 of a multi-series of international standards on general methods of test for pigments and extenders which covers comparison of resistance to light of coloured pigments of similar types.
ISO 787‑15 describes a general method of test for comparing the resistance to light of samples of similar types of coloured pigments (agreed reference pigment and test sample).
Two methods of exposure are described in ISO 787‑15. In method A, the material is exposed under glass to natural light. In method B, the material is exposed to direct artificial light
ISO 787‑15 on general methods of test for pigments and extender is useful for:
The terms “resistance to light” and “light fastness (or colour fastness)” describe the resistance of a material to change in its appearance as a result of exposure to light. The magnitude of the change, if any, is influenced by the quantity and quality of the light to which the material is exposed, and by the nature and composition of the material itself. Two compositions, each consisting of identical components but in different proportions, may not have the same resistance to light. Also, two compositions each consisting of the same proportions of similar, but not identical, components may not have the same resistance to light.
There are 2 methods mentioned in ISO 787‑15, these can help you in identifying the resistance to light of samples of similar types of coloured pigments which will help you understand how a material changes its appearance as a result of exposure to light.
BS EN ISO 787‑15:2019 supersedes BS EN ISO 787‑15:1995, which is withdrawn.
BS EN ISO 787‑15:2019 includes some technical changes with respect to BS EN ISO 787‑15:1995. Theses are:
ISO 787-15
EN ISO 787-15