David Prince 2015
A commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film (called "fountain solution"), keeping the non-printing areas ink-free.
Water-based aqueous coating can be applied over wet ink from a special coater tower. Aqueous seals a press sheet instantly allowing the ink to continue to dry underneath. Matte, dull and lay flat aqueous are recommended for uncoated paper. Aqueous coatings generally cover the entire sheet because they do not yellow over time. Like varnish, aqueous coating primarily prevents rub off.