The Practical Assessment of the Light Fastness of Dyeings

The testing of light fastness of dyeings against standards such as those originated by the Society is considered. It is shown that in practice certain anomalies are found, since the sample and dyeing do not necessarily follow the same course of fading. The discrepancies are examined on the basis of simple theory, and certain recommendations are made in respect of the practice of light–fastness testing. The influence of quality of light, atmosphere, and mixture of dyes is discussed.