Gravure cylinder
In gravure the printing form is typically a steel cylinder with a thin copper coating applied by electroplating. Cylinders for packaging printing can have a face length of up to 1.8 m and a circumference of up to 0.9 m. In special processes, e.g. for printing publications or laminate floors, cylinders with a roll width of up to 6.00 m are used. Depending on the engraving process, a further layer of zinc (for Direct Laser System) or copper is added as well as a special surface processing with the help of a grinding process. In this final layer the printing image is engraved in the form of deeply positioned cells. The engraved copper/ zinc layer is then chromed in order to achieve better durability. The engraving process in gravure allows an exact and reliable reproducibility of the print result. After printing the chrome layer as well as the copper or zinc layer is removed mechanically or chemically so that the cylinder body can be reused.
See also laser engraving and electro-mechanical engraving.