A method of printing in which the lines of the design are cut into metal, which are recessed to retain the ink. The paper is forced under pressure into these lines to pick up the ink. Hence engraved cachets appear to have the design raised above the paper surface.
The engraving method allows ink to settle into the engraved lines of the plate. In wet printing, which was common until the 1950's, wet paper is pressed into the grooves thus transferring the ink to the paper, in a sense placing the ink on the surface of the paper. This resulted in the ink being slightly raised, a fact which is immediately apparent when one rubs a finger across the surface of the engraved stamp.