When many printers use the fountain solution, they only pay attention to the pH of the fountain solution to be controlled within the required range (pH 5.0 to 5.4), ignoring the concentration of the fountain solution. In fact, when the concentration of the fountain solution changes greatly, its pH value does not change significantly. Therefore, it is unscientific to control only the pH value. Because the change of concentration will change the composition of the ink, which will affect the ink balance; the change of the fountain solution concentration will also cause the change of the surfactant concentration, which will cause the change of the surface tension, and finally affect the dampening effect, resulting in the quality of the printed product. decline. Therefore, the concentration of the fountain solution is a key factor affecting the quality of the printed product. We must control the concentration of the fountain solution while maintaining a stable pH.