Stripper-harvested cottons, varying in trash content as a result of differences in growing season and ginning treatment, were processed from bale to silver, collecting and weighing wastes and determining their non-lint contents. The results show that the waste extracted from a cleaning machine, or combination of such machines, operating on impact principles bears a linear relationship with the non-lint content of the cotton supplied. The comparable relationship for filter waste, which includes flat strips from the carding operation, is almost constant, explaining the apparent tendency for card cleaning performance of a cleaning machine, or a group thereof, is shown to be dependent upon the non-lint content of the bale and independent of ginning treatment, season, bale compression, or the level of bark assigned during cotton classification.