Advantages of offset printing
Advantages of offset printing compared to other printing methods include:
- Consistent high image quality. Offset printing produces sharp and clean images and type more easily than letterpress printing because the rubber blanket conforms to the texture of the printing surface.
- Quick and easy production of printing plates.
- Longer printing plate life than on direct litho presses because there is no direct contact between the plate and the printing surface. Properly developed plates running in conjunction with optimized inks and fountain solution may exceed run lengths of a million impressions.
- Cost. Offset printing is the cheapest method to produce high quality printing in commercial printing quantities.
- A further advantage of offset printing is the possibility to adjust the amount of ink on the fountain roller with screw keys. Most commonly a metal blade controls the amount of ink transferred from the ink trough to the fountain roller. By adjusting the screws the gap between the blade and the fountain roller is altered, leading to the amount of ink applied to the roller to be increased or decreased in certain areas. Consequently the density of the colour in the respective area of the image is modified. On older machines the screws are adjusted manually, but on modern machines the screw keys are operated electronically by the printer controlling the machine, enabling a much more precise result.[7]
From Wikipedia
18 March, 2012
