Prepress processes occur between the print layout and the actual printing. The prepress process includes all steps which lead to the final print project. A prepress process includes manufacturing a printing plate, image carrier, preparing for mounting on a printing press as well as adjusting images or texts in the file.

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What is offset printing?

Offset printing, also known as offset lithography, is the most commonly used printing method around the world since the 20th century. It operates on the principle that ink and water do not mix, allowing for the creation of high-quality prints with precise color accuracy and sharp details. The offset printing process involves transferring ink from a plate to a rubber blanket and then to the printing surface, making it possible to print on a variety of materials such as paper, cardboard, and plastic. The name “offset” comes from the fact that the image is first transferred to another surface before it is printed on the final paper. This process is highly efficient, cost-effective, and reliable, making it the preferred choice for many commercial printing applications.

How is offset printing done?

The information of the image (the artwork and text) is put on thin metal plates, which are water dampened. The ink goes onto the rollers on the press. The oil-based ink adheres to the image area, where the water adheres to the non-image area. The inked area is transferred to a rubber cylinder, called a “blanket”, where the inked area then goes onto the printing surface as the paper passes.

Modern offset printing is done on a press with basically three rotating cylinders: a plate cylinder, to which the metal plate is fastened, a blanket cylinder covered by a rubber sheet and an impression cylinder that presses the paper into contact with the blanket cylinder. The plate cylinder encounters a series of moistening rollers. A series of inking rollers then pass over the plate and the ink is accepted by the image and at the same time rejected by the water-holding areas. The inked image is transferred to the rubber blanket and is than offset to the paper which is travelling around the impression cylinder.