Cotton was commercially grown in a uniform field in the Texas High Plains area, stripper harvested and ginned by two methods to obtain bales with low and high bark concentrations. Bark contents were determined gravimetrically from manual extractions of 25-gram samples of raw stock. Three groups of five mixes were prepared from the low and high bark cottons as follows: (1) 100% low bark, (2) 75% low bark/25% high bark, (3) 50% low bark/50% high bark, (4) 25% low bark/75% high bark, (5) 100% high bark. One group of five mixes was processed through standard textile cleaning, carding, and drawing equipment and spun on a modern rotor spinning frame to determine the effect of each mix (and thus varying bark levels) on processing efficiency and yarn quality. The second group was processed identically to the first except for a tandem card was used for carding. The third group was processed on modern state-of-the-art cleaning and carding equipment and spun on the same equipment used for groups one and two. Bark content did not significantly affect yarn quality for either of the three processing sequences. However, yarn breaks in spinning increased approximately 60% for each 1% increase in bark content of raw cottons for the cotton processed on standard textile equipment. Processing efficiency was not significantly affected by bark content when tandem carding or modern cleaning and carding equipment were used.