Paul D. Fleming III, Paper Engineering, Chemical Engineering and Imaging
Gravure transfers ink from small wells or cells that are engraved into the surface of the cylinder. This is illustrated in the figure below. The cylinder rotates through a fountain of ink. The ink is wiped from the surface by a doctor blade. The cup-like shape of each cell holds the ink in place as the cylinder turns past the doctor blade.
The formation of nearly perfect cells or wells is accomplished by the gravure engraver. The gravure cell is characterized by 4 variables; depth, bottom, opening and bridge. The depth of the cell is measured from the bottom of the cell to the cylinder surface.
The opening is described by shape and cross sectional area. The bridge is the surface of the cylinder between cells. The doctor blade rides along the cell bridges or ridges (also called walls).