sügavtrükk

Sügavtrükk, also known as intaglio printing, is an image transferring process where the image is created by incising a design into a printing plate. The plate is then inked, and the ink settles into these incised areas. Excess ink is wiped from the surface of the plate, leaving ink only in the recessed grooves. When paper is pressed onto the inked plate, the ink is transferred from the recessed areas to the paper, creating the printed image.

The depth and width of the incised lines determine the amount of ink that can be held and therefore the tonal value of the printed area. Deeper and wider lines hold more ink, resulting in darker tones, while shallower and narrower lines hold less ink, producing lighter tones. This principle allows for a wide range of tonal gradations and fine detail in the printed image.

Historically, sügavtrükk techniques included engraving, where lines are cut directly into the metal plate with a burin, and etching, where acid is used to bite lines into a protective coating on the plate. Modern sügavtrükk, particularly in commercial printing, often utilizes photogravure or rotogravure processes. In photogravure, a photographic image is transferred to the plate, and then etching creates the recessed cells. Rotogravure uses a similar principle but employs a rotary cylinder for high-speed printing, commonly used for magazines and packaging. The characteristic feature of sügavtrükk prints is their raised ink lines, which can often be felt when running a finger over the printed surface.