To provide a method and a device for improving wetting water characteristics in offset printing.

The method and the device are used for optimizing the characteristics of wetting water for an offset and roto-offset printing machine by a separation and removal means for ink, bubbles, and a printing residue (such as paper and a solvent), which are discharged from return water to printing components up to an existing re-circulating unit through drop by gravity or a re-transporting base.