Flachdruckprinzip

Flachdruckprinzip refers to a printing technique where the printing and non-printing areas are on the same level. This principle is the foundation of lithography and offset printing. In these methods, the differentiation between printing and non-printing areas is achieved through the chemical properties of water and oil. The printing surface is treated so that the image areas attract ink and repel water, while the non-image areas attract water and repel ink. When ink is applied, it adheres only to the image areas.

The process typically involves a flat plate, often made of stone or metal. First, an image is drawn or transferred onto this plate using a greasy substance. The plate is then dampened with water. The water adheres to the non-image areas, which have been treated to be hydrophilic, while the greasy image areas repel the water. Ink, which is oil-based, is then rolled over the plate. The ink adheres to the greasy image areas and is repelled by the water in the non-image areas. The inked image can then be transferred to paper or another substrate, either directly or indirectly through a rubber blanket as in offset printing. This indirect method is common as it allows for printing on a wider variety of surfaces and reduces wear on the printing plate.