Abstract: An algorithm for modulating printer half-tone screening based on the tonal values of the region being reproduced is provided. The algorithm determines the tonal values for a particular region and assigns real number constants to that region. As the clustering screen is applied, the threshold values in the clustering screen are reduced (divided) by the real number constants thereby modulating the effect of the application of the clustering screen. For deep tonal regions, the clustering screen is applied at full strength, while in light tonal regions no clustering effect is applied. The algorithm results in a an image that has a greater dynamic range without the appearance of stair stepping while eliminating clustering artifacts from the lighter regions.