Greenprint Guide to Gravure printing
Gravure printing is a widely-used printing process. Whereas litho uses a planographic (flat) surface to transfer the image, gravure uses an intaglio (Italian = "cut-in") surface, where the image is etched or engraved into a hard surface, using ‘cells' (holes) of differing depth. The ink is applied to the surface area and a doctor blade is used to squeegee the excess ink from the un-etched surface, leaving ink in the cells which form the image area. The deeper the etching, the more ink it will hold. The material to be printed is then applied to the surface and the ink is deposited. More ink can be applied that is possible using litho, so deeper colours can be achieved and surface imperfections of the material can be covered over by the heavier film of gravure ink. Rotogravure denotes a printing press which uses a cylinder which is etched or engraved and reels of paper (or other materials) are fed through the press where the inks are printed in sequence one after the other using one printing unit per colour.
Gravure printing is used to print high quality magazines, catalogues, wallpaper, postage stamps, laminates for kitchen worktops, vinyl flooring and for printing onto fabrics. Generally speaking, the quantity must be very large (usually several hundred thousand impressions) to justify the high set-up cost of producing the etched cylinders, although advances in digital technology are lowering the cost of gravure cylinders, bringing down the minimum viable quantity for gravure printing.