A member of the Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland, outlines in a simple way some of the basic principles of the fading of textile coloring matters. Based on a paper presented to the International Institute of Conservation conference on conservation of textiles, Delft, The Netherlands, July 7, 1964. Discusses the nature of colored materials, light fading, lightfastness measurement, circum-stances which affect lightfastness, gas fading, catalytic tendering by light, and safeguards against fading.