The first observations of the nuclear magnetic resonance (NMR) phenomena were reported in 1946 by Purcell [1] at Harvard University and by Bloch [2] at Stanford University. Since that time, NMR spectroscopy has experienced a remarkable growth and is presently one of the most useful instrumental techniques for the Study of chemical systems. During 1967 more than 2500 papers were published relating to some phase of NMR. Unfortunately, very little work has been done in NMR spectroscopy in relation to coatings chemistry. This is probably due to two major factors. The first of these is the high cost of the instrumentation involved, usually more than $30,000, and the second factor is a lack of knowledge of this technique by most coatings chemists. In regard to cost, as many coatings companies are finding out, the instrumentation will certainly pay for itself in a short time. A lack of knowledge of this technique by most coatings chemists was the inspiration for this chapter.