Phenol/Formaldehyde resins are a main component of the photosensitive coatings used to make circuits in computer chip preparation. Since the resins are formed in reversible acid catalyzed reactions, they are prone to unwanted mixtures of various molecular weight fractions. This paper outlines various techniques (steam distillation, base neutralization etc.) to stabilize the molecular weight distribution of the resins and prevent reverse reactions from occuring. Performance characteristics of the resins were further optimized by selectively fractionating the resins and this paper will compare the various fractionation methods used to make the best resins used for making micro-circuits.