To understand rotogravure printing, a brief primer of intaglio is required. Intaglio is the process used in printing and printmaking in which an image is incised into a surface and where the incised line – or sunken area – holds the ink. There are many applications for intaglio, such as the decoration of armor, musical instruments, and religious objects, as well as mass-printed stock certificates, maps, magazines, newspapers, fabrics, sheet music, wallpapers, banknotes, passports, and high-value postage stamps.
also look at copper engraving
or Aquatint
