The Improvement of Luster of Cotton: Part I: Measurement of Reflectance Characteristics Related to Luster

Practical details are given for using two different instruments for measurement of the reflectance aspects of the luster of cotton yarns. Typical reflectance curves for cotton yarns differing in luster because of mercerization are discussed and compared with the reflectance and visual properties of fabrics made from these yarns. The physical measurements on yarns are much better correlated with what the eye sees in the yarns or in the fabrics than are the meas urements on these particular fabrics. This indicates that the study of yarns by these methods is useful both for yarn and fabric. In winding the yarns for examination, a cover factor of more than 40 is found to be needed to eliminate the effect of the backing. Other points of tech nique, such as tension in winding, humidity, and the size of apertures in the optical system, produce small variations which, however, need to be cared for by standardization of technique when small differences in luster are being examined.