Pima cotton is roller ginned to preserve fiber quality. Roller-ginning rate (about 1.5 bales per hour for a 40-in. wide roller) is limited by the rate that fibers adhere to the roller and slip under the stationary knife. Increasing roller speed increases ginning rate, but produces higher roller temperatures due to friction. Roller covering material currently used is made from layers of woven cotton fabric bonded together with a rubber compound. A more aggressive roller cover may pull more fiber under the stationary knife, increasing ginning rate at normal roller speeds and reducing heating at higher roller speeds. An experimental roller covering, made from woven fiberglass, was tested to evaluate it's ginning performance and effect on fiber quality. Tests were run at normal ginning rates (1 to 1.5 bales per hour) with no lint cleaning and randomized with a standard roller covering. Raw lint fiber tests included High Volume Instrument (HVI) measurements, Advanced Fiber Information System (AFIS) measurements, and Shirley Analyzer measurements. White-spec analyses were also performed on the spun lint to detect contamination levels. The experimental roller covering was much more aggressive than the standard covering: it ginned at twice the rate (2.4 vs. 1.2 bales per hour) at a much lower controller setting and resulted in less roller heating (91 vs. 153 °F average). There was more trash, based on HVI and AFIS measurement, in the lint from the experimental roller, but there were no significant differences in other raw fiber measurements between the experimental and standard roller coverings.