A drying stimulator is a water base solution of a compound such as cobalt chloride, cobalt acetate, or manganese nitrate. The proportion is 1-2 ounces/gallon of dampening solution. Cobalt and manganese accelerate the drying of inks that contain drying oils. Drying stimulators can be used to help ink drying and are available from graphic arts supply dealers. Drying stimulators can cause the ink to dry more quickly on the roller in the press and should be used carefully.