Isopropyl Alcohol alters the viscosity and flow characteristics of water solutions without alcohol do not flow as well and will need less nip pressure between the rollers. Alcohol is a solvent that dilutes the ink, and when running with an alcohol replacement fount less ink and water should be required to produce acceptable colour. Alcohol reduces surface tension of the dampening solution. Surface tension is the microscopic attractive force between liquid molecules that makes water form a droplet When this force is reduced by alcohol. the droplet “relaxes”, and the same volume of water will spread thinner to cover a greater area of the plate. This spreading is sometimes referred to, quite correctly, as wetting. Since alcohol is used in such a high concentration, usually around 10% the alcohol molecules are abundant and will migrate very quickly to the surface of the water, which is where we need their surface tension-reducing abilities. This can be important with a high speed dynamic process like printing.