Similigravure

Similigravure (or similigraphie) [Halftone engraving or printing, or just halftone] is a printing technique allowing the reproduction of a monochrome document made of halftones transcribed into halftone dot values, with value gradation ranging from white to black ['demi-teinte'].

Licensed by French printer Charles-Guillaume Petit in 1878, the technique was developed by Georg Meisenbach and perfected from 1890s by the Levy Brothers in the US.