This determines the acidity and alkalinity of a paper. The degree of the acidity or alkalinity is measured by a scale ranging from 0 to 14, with 7 being a neutral point. Measuring the pH value of a paper is important in the preparation of plate making chemicals, as well as making paper and pigments. Controlling the pH of press fountain solutions is also crucial in assuring that uniform ink drying and maximum plate-life is achieved. On the scale, 0-7 is acidic and 7-14 is alkaline. 7 is neutral.