Abstract: A method of controlling the drive of the electric pretensioning unit of rotary printing machines having individually driven rotary printing cylinders and folders is specified, so that, in the event of changes being made to the paper grade or to the production sequence without the machine being stopped, only slight web tension changes occur, and the operating limits with regard to web tension are reliably maintained. This method is equally well suited to rotary printing machines having individually driven printing units or printing bridges and folders and to conventional printing machines that are driven by mechanical shafts via couplings.