Etching
The essential principle in etching is that the metal of the plate is removed, to a degree, by eating into the surface with acid, rather than cutting with a tool such as in engraving or woodcutting. The plate is first coated with a ground, impervious to acid, through which the artist draws to expose the metal. Next, the whole plate is immersed in an acid bath until the lines are sufficiently “bitten”. Finally, the ground is removed and the plate is inked and printed in the usual Intaglio way.
Drypoint
Drypoint is the simplest of all the Intaglio processes. The line is scratched directly into the copper plate with a sharp metal point, the "drypoint needle". As the needle scores the copper, it throws up on both sides of the line a ridge of metal known as a “burr”. This “burr” is responsible for the most characteristic effect of a drypoint, that being that the curled metal holds a quantity of ink which prints as a rich feathery smudge.
Woodcut
The material used for a woodcut is a wooden block, usually about one inch thick. Before the wood is used, it must be seasoned so it will not wrap or crack. The artists design is either drawn directly on the block, or a sheet of paper which is glued onto the wood suface. Chisels, gouges, and certain types of pen-knives are used to cut away sections of the wood. When finished, the remaining raised images will be left standing out in relief, which are then inked and hand rubbed in printing.
Lithograph
Lithography is based on the principle that grease and water repel each other. The printing surface is predominantly limestone, whence the term lithograph which means “stone drawing”. The artists marks are drawn on the stone in some greasy medium. In printing, the stone is dampened with water, which settles in the unmarked areas. Secondly greasy printing ink is rolled onto the surface and adheres only to the grease lines drawn, and is repelled everywhere else by the the watered surface. Finally the ink is transferred to a sheet of paper via a flat bed press, or rubbing by hand, to produce the relief print.
Intalglio
Intaglio is a general name for any printmaking method using metal plates including the afore mentioned engraving, etching and drypoint. Lines are cut or etched into the metal, and ink is pressed into lines with a “dauber”. Whatever ink is left on the uncut surface of the plate is wiped away. Dampened paper is then placed on the plate and the two are passed through a flatbed press, so that the paper is forced down into the incised inked lines, and the print is made.