96 the most versatile process in print- making in which the line or area that make the impression is cut into the lower than the general surface of the metal plate, holds the ink which is drawn out on the paper in printing by the great pressure of the press. It includes engraving, mezzotint, drypoint, line etching, and aquatint. KEY PLATE OR BLOCK The plate or block used to serve as a guide to register other plates or blocks in color printing. LIFT GROUND To etch a positive image on aquatint by drawing with a water soluble ground. LITHOGRAPHY Type of printing based on principle that oil and water will not mix. MEZZOTINT A method of creating a dark surface by roughing up the plate with the tool called a ROCKER, and working back toward the light tones by scraping and burnishing. MIXED MEDIA To work with a combination of techniques on the same print. OFFSETTING Indirect printing, by depositing an image on a roller or plate surface and then from there to the paper. PLANOGRAPHY Process of printing from a flat surface, based on inability of water- wet surface to take ink. PHOTO-ENGRAVING Printing cut or plate in which printing surface is in relief, made by photochemical process. RETROUSSAGE To pull the ink out of the lines lightly on an otherwise cleanly wiped plate; to make the linear or tonal areas richer. R ELIEF ETCHING The design stands out in relief; the rest of the plate is etched down. STEEL FACING To deposit a thin layer of steel by galvanic process on the surface of the copperplate to make it more resistant to wear. STIPPLE PRINT To create a half-tone effect by engraving and etching little dots into the plate.