Rotogravure

Rotogravure printing is the most direct form of rotary printing. This process makes use of copper cylinders that are partially immersed in ink wells. The cylinder itself is engraved through etching, forming a multitude of small impressions in the cylinder. These impressions are filled with ink as the cylinder rotates in the inkwell and then the ink is transferred onto the substrate as it passes between the etched cylinder and the impression cylinder. This process can be used to create color images by using several etched cylinders immersed in different ink colors, though the ink must be dried between color applications.

Differences between offset lithography and rotogravure:

---- More refined

---- Copper not Zinc plates

---- Reversed image

---- More expensive

---- Denser ink coverage

---- High volume and durable jobs

If you ignore the strange choice of music then this video illustrates the process well: