The precision of measured cotton strengths before and after correction using near infrared spectroscopy has been investigated. A collection of 54 cottons were analyzed at a variety of humidities with strengths and spectra determined in duplicate. Strength correction factors were generated from NIR spectra collected simultaneously and the results show that the variability due to the moisture content of the cottons is greatly reduced while the repeatability as measured by standard deviation of duplicate measurements is not statistically affected.