In a method to operate a digital printer having multiple developer stations operated with liquid developer, and wherein a number of the developer stations participating in printing is dependent on a respective print operating mode, liquid developer is supplied from a mixing container to at least one of the developer stations. With a regulatory device a fill level of liquid developer in the mixing container is kept substantially constant depending on the print operating mode. A desired different operating value is provided for the fill level for the regulatory device depending on the operating mode.