a process for controlling the amount of film buildup on a photoreceptor surface caused by certain print mode and / or material through conditions in a single pass highlight color printer which enables or promote photoreceptor filming by the dad toner additive . such filming results in tri - level image push defect . this process utilizes toner coated cleaner brushes to control the film buildup thus preventing the defect . this process defines a functional equation that maintains a certain toner concentration at the cleaner brush fiber tips thereby controlling photoreceptor filming .