The offset printing (lithography) covers the dominating share in the world printing market – around 50%. The advantages of this printing method, mostly valued by the customers, are the high printing quality and low preparation costs. When comparing to the flexographic printing, the ink dosage and transfer mechanism of the offset printing is much more complicated. There is used thick oil-based or UV ink, which is transferred to the form via a number of steel and rubber rolls. Before applying ink, the printing form passes the watering section, where non-printable areas of the form are absorbing water. Then the form on the printing cylinder passes the inking section and ink is deposited on these areas of the form, which have repelled water (printing areas). Further the rotating printing cylinder transfers ink onto the roll coated with the rubber of special type which transfers ink onto the printing material. Ink dosing in the offset printing is accomplished by adjusting pressure of the ink-removal knives and so adjusting the thickness of ink layer on the steel ink-transfer roll. Such principle of ink dosing enables to change smoothly amount of ink transferred, however, it is more complicated to adjust to the each separate order and colour may change in time of printing by itself when ink viscosity changes. Additionally, there is very important to adjust correctly water balance. Summarising, it may be said, that the offset printing sets higher requirements to qualifications of printing operators, additionally, machine adjusting takes more time and spoils more material as compared to flexographic or intaglio printing. | 
