1. A method for regulating the ink-to-wetting agent equilibrium in a rotary offset printing machine, comprising the steps of: presetting a wetting agent quantity supplied to a printing form; calibrating the wetting agent quantity supplied at a certain ink quantity; adjusting the wetting agent quantity to a wetting agent quantity setpoint value that is characteristic for a specific print job; increasing or decreasing the ink quantity from an ink quantity setpoint value to an ink quantity target value desirable for the specific printing job; increasing or decreasing the wetting agent quantity setpoint value in a same direction as the increasing or decreasing of the ink quantity to a wetting agent quantity target value; and regulating the wetting agent quantity supplied in a closed control loop as a function of the wetting agent quantity target value.