The purpose of this method is to evaluate the color fastness of textiles of any nature and shape, with the exception of staple fibres, to the action of bad weather as achieved by exposure in a device equipped with a xenon arc lamp. If there is a possibility that the color is phototropic, the phototropic test should be applied.
UNI 7931-1979 history
1978UNI 7931-1979 textile. Color stability test, stability against adverse weather effects. Xenon lamp irradiation