mélynyomási

Mélynyomási, also known as photogravure or gravure printing, is an intaglio printing process. In this method, the image is etched onto a plate, typically made of copper, and then inked. The ink fills the recessed areas of the plate. During the printing process, excess ink is wiped from the surface of the plate, leaving ink only in the etched depressions. A sheet of paper is then pressed against the plate, transferring the ink from the recesses to the paper.

The depth of the etched areas directly corresponds to the tonal values of the image. Deeper etchings hold more ink and produce darker tones, while shallower etchings hold less ink and create lighter tones. This results in a wide tonal range and the ability to reproduce fine detail, making photogravure highly regarded for its artistic quality, particularly in the reproduction of photographs and fine art.

The process begins with a photographic positive, which is used to create a carbon tissue. This tissue is then transferred to a copper plate that has been coated with a light-sensitive material. The plate is exposed to ultraviolet light through the positive, hardening the light-sensitive coating in proportion to the light intensity. Subsequent etching with a ferric chloride solution dissolves the unhardened areas, creating the recessed image. The depth of the etch is controlled by varying the strength and duration of the etching baths.

Historically, photogravure was a significant medium for fine art printing and book illustration due to its ability to achieve rich, continuous tones and subtle gradations. While modern digital printing technologies have become more prevalent, photogravure remains a favored technique for artists and printmakers seeking its unique aesthetic qualities and archival permanence.