CHROMATOGRAPHY IS A TERM THAT DENOTES a myriad of laboratory separation processes based on a differential migration phenomenon. It is particularly effective for the resolution of complex mixtures; hence, it can be used as a chemical preparatory method or, more importantly, as an analytical tool. This potent analytical technique has been widely used in the paint industry for a broad range of coating applications from everyday routine analysis tofundamental research into the nature of organic coating systems. Its use has been so extensive that virtually every type of material used in paint has been affected by chromatography.