Offset rotary machine with at least one printing unit

In an offset rotary machine including at least one printing unit with a plate cylinder, a rubber blanket cylinder and an impression cylinder, and an inking mechanism and a dampening mechanism for the plate cylinder, the printing unit including first and second plate cylinders arranged at a predetermined distance from each other, means for moving the first and second plate cylinders on a common coordinate between a first position and a second position, the inking mechanism including an inking roller, the first plate cylinder being in contact with the rubber blanket cylinder and the inking roller when the plate cylinders are in the first position and the second plate cylinder being in contact with the rubber blanket cylinder and the inking roller when the plate cylinders are in the second position, the improvement comprising the dampening mechanism including a dampening roller, the dampening roller being in direct contact with the inking roller, wherein a cylinder gap is defined between the two plate cylinders, further comprising means for adjusting the inking roller relative to the cylinder gap between the plate cylinders.