The pH of a large number of experimental and commercial papers was determined by the TAPPI Standard T 435 cold-extraction method and a method in which glass-calomel electrodes were pressed against the surface of the papers, moistened with either distilled water or 0.1 N KCl solution. The use of potassium chloride solution instead of water gave better reproducibility, less time variation, and values, on an average, about 0.4 pH units lower. Correlation between the spot tests and extraction pH's was rather poor, especially for papers of high extraction pH. Few generalizations could be made concerning the effects of the types of pulp or added chemicals upon the pH values. It appears that other variables in the paper-making, blending, and pulping cause considerable variation in measured pH values of the paper. Because of the complicated nature of the chemical and physical processes involved, none of the methods can be judged to be superior to the others per se, but the spot test merits consideration in cases where a quick, nondestructive method is needed. -- CCI