n A theory describing the optical behavior of materials containing small particles which scatter and absorb radiant energy. It is widely used for color matching calculations. The mathematical equation describes the reflectance or transmittance in terms of an absorption coefficient, K, and a scattering coefficient, S. The K-M theory is based on an assumption of multiple scattering, that is, reflectances from one particle on to other particles before the reflected radiant energy is observed. This assumed behavior is in contrast to the Mie Theory which is based on an assumption of single isolated scattering of individual particles. (Colour physics for industry, 2nd edn. McDonald, Roderick, Society of Deyes and Colourists, West Yorkshire, England, 1997).