Excerpts from the report: Evaluation of the relative importance of measurable cotton fiber properties and other factors of raw-cotton quality to processing performance and product quality is the subject of continuing studies by the Cotton Division of the Agricultural Marketing Service. Such information and related equations derived from these studies are of value to cotton breeders in informing them of the fiber properties they should consider important in their programs, and helpful to the cotton trade and textile industry in choosing cottons best suited to the manufacture of specific products and for meeting various levels of product quality. This is a report of the results obtained from studies to determine the influence of yarn size on the relation of 6 fiber properties to skein strength of carded yarn; and a discussion of discrepancies in results obtained for 14s, the coarsest yarn studied. These findings suggest various problems for further experimentation and exploratory study, in the continuing effort to provide the factual basis needed for developing improved, more standardized, and better controlled methods of testing in cotton spinning laboratories and commercial textile plants. Included in this study are data representing a total of 842 cottons and 3,267 lots of long-draft processed, carded, warp singles yarn, ranging in size from 14s to 60s, with a semi-hard twist, for 3 crop years, 1948-50. Supplementary analyses were made with the data representing 277 cottons and 1,108 lots of yarn from the 1948 crop, stratified by variety and 3 dates of harvesting, for special analytical purposes.