Several mutant lines of cotton have been described in which specific phases of fiber development are altered. These mutants are invaluable tools for characterizing to quality. Since these mutant lines will be an integral part of our research approach, the physical properties of fiber from three mutants [pilose, immature fiber, and naked seed (expressed in the heterozygous state)] have been determined. Preparation of yarn and fabric from small scale-spinning and knitting of mutant fiber samples permitted yarn strength, yarn extensibility, and dye uptake by knitted fabric to be measured. The relationship between the physical properties of mutant fiber and their resulting yarn and fabric will be discussed.