GINQUAL, a digital simulation model, predicts cotton quality and quantity parameters as stripper harvested cotton is processed through different sequences of gin processing equipment. The simulation model tracks cotton quality, quantity and moisture content as it passes through each machine in the processing system and predicts grade as a function of foreign matter content and color levels of the lint. A wide range of cotton types with varying amounts of foreign matter and moisture was simulated using the model GINQUAL. The model tends to over predict the trash content at the ginstand feeder apron and to under predict the nonlint content after two lint cleaners. However, the overall results are satisfactory and the model can be used to examine different processing sequences for potential improvement in quality.