The purpose of this research was to establish the effectiveness of louvers installed on the 24D lint cleaner in terms of gin and mill performance. Previous research has shown that the use of available number of grid bars at a cotton gin results in improved value for the final product primarily by reducing the waste detected by the lint cleaner. 24-in. wide, glass-sided, 24-D lint cleaner was modified to add automated louvers. Two varieties of cotton were selected for comparison with the modified lint cleaner. These varieties were Deltapine 50 and Stoneville 4691B. Grid bar combinations utilized for each test per variety ranged from one to seven. Analysis of variance indicated that variety had a significant impact on nearly all factors, with the exception of lint moisture content. Grid bars had a significant effect on lint waste, leaf grade, HVI trash, Shirley Analyzer waste; AFIS dust count, AFIS trash count, AFIS visible foreign matter, and Opening and Cleaning waste. There was a significant effect of variety on Leaf grade, HVI Trash, SA waste, and Opening and Cleaning waste, making it necessary to consider these factors within each variety. With respect to opening and cleaning waste, the number of grid bars utilized significantly impacted the amount of waste generated. As for ring spun yarn quality and spinning efficiency, the number of grid bars utilized during ginning at the lint cleaner alone had no significant effect on either parameter.