THE analysis of coatings is a broad topic and for this brief, critical review of the literature, it is practically necessary to define and limit the field of view. The term "coatings" might embrace every material that could be spread on a surface or incorporated into a film. By far the most common matrices, however, are those organic high-polymeric substances into which may be incorporated oils, plasticizers, waxes, fillers, pigments, etc. For brevity, the authors have arbitrarily omitted important classes of coating materials such as vitreous enamels and metallic platings.