Various attributes of cattle coats are evaluated in terms of their repeatability and heritability, and their capacity to discriminate between coats of different breeds, but principally in terms of their correlations with a subjective coat score, with skin temperature, and with growth rate. The correlation of 0.7 between growth rate and coat score is almost equalled by the multiple correlation between growth rate and a group of measured coat characters. Of these objective characters contributing to coat type, the depth of coat and the hair diameter are most important, followed by the percentage of medullated hairs and the maximum length of fine hairs; hair curvature and follicle angle contribute little. Bonsma's felting score provides a useful indication of coat type, but it is consistently inferior to a coat score. Weight of hair per unit area of skin is unreliable, because it is dependent on length and diameter, which have opposing effects on coat quality. The relative value of different characters varies with circumstances. In late spring, depth was the most important measurement but in winter and early spring it was exceeded in importance by a score of the amount of "body" in the coat. Though coat score is defined fairly completely in terms of component characters, it remains of greater value than any other assessment, presumably because it refers to the whole coat in situ, rather than to a small sample of clipped hair.