A method of printing images in a liquid electrophotographic printer is provided. In an example, the method includes measuring at least one current associated with an image development unit of the liquid electrophotographic printer. A first time at which a peak occurs in the measured current is determined; the first time indicates that a printing substance is transferred from a point on a developer roller of the image development unit to a photo imaging member of the liquid electrophotographic printer at a first location within the image development unit. A second time at which said point on the developer roller is expected to contact the cleaner roller within the image development unit is calculated and, at the second time, a voltage applied to the cleaner roller is controlled to reduce the potential difference between the cleaner roller and the developer roller.