You searched for: “chemigraphies
chemigraphy (s) (noun), chemigraphies (pl)
1. Any mechanical engraving process depending upon chemical action; specifically a process of zinc etching without the aid of photography.
2. A process of obtaining half-tones by printing, from the same plate, in two colors, or two shades of the same color, one of which is slightly out of register.
3. In graphic arts, any of various nonphotographic chemical processes used to make etchings or engravings.