Of great concern to textile conservators is the ever-present range of yellow, orange, and brown stains, most commonly observed on white or light colored textiles and which are generally described as iron stains. While being aesthetically unpleasing, no published studies of these stains have yet resolved the problem of whether or not treatment is required; nor have details of their nature or degradation factors been provided. Treatments currently recommended have been found to be ineffective in many cases or to have caused only a temporary effect. Research is, therefore, being conducted to identify, classify, and analyze these stains on textiles and to examine their close relationship to similar stains on paper and to corrosion science. Preliminary results of the research are recorded. To date it has been possible to describe and analyze four basic stain types for which non-destructive methods of identification are described. It is hoped that an understanding of their nature and degradation processes will aid in the examination of the causes and development of these stains, and aid in formulating preventive methods for textiles in long temn storage. The necessity for treating each of the categories of stains so far described or providing means to stabilize the degradation is being investigated in conjunction with a re-evaluation of currently recommended treatments.