Abstract: Rotary printing press is provided with mounting means for an image cylinder to facilitate interchange of cylinders of different sizes and their adjustment. The cylinder is carried on upstanding supports on a cradle, end stub shafts of the cylinder being journalled on said supports and one or both of the latter being adjustable longitudinally of the cradle to suit cylinders of various axial lengths. The cradle is movable in a frame of the press either horizontally so that it can be withdrawn as a unit with the cylinder, or vertically for forming a nip with an impression cylinder.