gravure
A type of intaglio printing process, in which an image is engraved onto a rotating copper cylinder.
gravure: high-speed intaglio printing from an etched cylinder
Gravure is a rotogravure process where an engraved copper cylinder transfers ink to paper or film at speeds up to 300 meters per minute. Unlike letterpress or offset lithography, the image sits below the cylinder surface in tiny etched cells, each holding a precise volume of ink. When the cylinder rotates through an ink bath and then presses against substrate, these cells release their contents in a single pass, producing fine detail and consistent color density.
The copper cylinder is prepared by electroplating a hardened steel core, then the image is engraved photochemically or by electron beam, creating cells typically 10 to 40 micrometers deep. Cell depth and width determine ink quantity, allowing gradation across the image through variable cell size rather than halftone dots. This produces photographic quality particularly valuable for packaging, decorative laminates, and high-volume publications where tonal fidelity matters.
Variants and applications
Hell gravure uses electronic engraving to cut variable-depth cells based on image scans, replacing chemical etching. This speeds make-ready and allows fast job changes. Helio gravure, the traditional photographic method, demands longer setup but remains economical for very long runs. Both require cylinders 200 to 800 millimeters in diameter and one to three meters in length, making them heavy capital equipment suited to dedicated facilities.
The process excels with thin substrates: 12 to 80 micrometer films for laminates, 40 to 120 gram papers for catalogs and magazines. The reverse of the cylinder pushes rather than impacts, so fragile materials stay undamaged. Gravure also tolerates surface texture and moisture variation better than offset, a real advantage when printing layered materials or recycled fiber.
Maintenance dominates costs after initial cylinder investment. Worn or scratched cylinders cannot be repaired in situ and must be recoated, a process taking weeks. The doctor blade that removes excess ink from the cylinder surface wears constantly and must be adjusted or replaced regularly. Screen deposits and ink drying in cells demand frequent washouts, and solvent recovery systems add capital and operational complexity to any gravure installation.