A 2,117-bale optimal blending experiment was completed in a 4-week period by processing three different types of cotton to produce 6/1 ring spun yarns and by weaving them into a style of denim fabric. The HVI data and lab test results on tensile properties of yarns and fabrics were analyzed to see if the HVI elongation variances can be used as a criterion for maximizing the yarn and fabric strengths. The study has shown that the variance of breaking elongations obtained directly from HVI tests on bales selected for a given laydown is not proportional to that of the single fiber breaking elongations within the same laydown. Therefore, it was concluded that HVI elongation data, in their raw form, are not useful as a criterion for bale selection. Based on a new model for estimating single fiber tensile properties from HVI bundle tensile data, the variance of breaking elongations was estimated for all fibers contained in each laydown. The simulated bundle tensile properties from these converted tensile data were applied in analyzing the experimental data from the study. The simulated tensile properties of small bundles (6/1 single yarn) together with HVI fiber length provided a useful method for optimizing the yarn and fabric strengths. MANTIS single fiber test results were used for obtaining the single fiber tensile properties from the HVI bundle data.