By appearance measurements, we mean color measurements and measurements of geometric appearance such as gloss, opacity, and luminous reflectance. Economically, such measurements save money by eliminating costly uncertainties and arguments, by identifying the least expensive combinations of ingredients in processing that will produce the required final result, and by guiding the development of economically profitable new products. Functionally, such measurements are used for product research and development, color formulation and batch adjustment, quality control, and evaluations of product performance.