Printmaking knows three groups of techniques: relief printing, planographic printing and intaglio printing.
In relief printmaking - woodcuts, wood engravings or linocuts -, everything that is not meant to be printed gets cut away. The raised surface is then inked/painted and then the print is produced by some kind of a pressing process.
The intaglio printmaking technique works the opposite way. A line is incised into the surface with various tools. The print is produced by pressing a sheet of paper against the plate. The intaglio printmaking techniques are engravings, such as drypoint, etching, aquatint or mezzotint.
Lithography is a planographic technique where the medium itself does not get physically altered by incision or carving. The artist applies his artwork on the surface of a stone block.
Engraving, etching - Intaglio Printmaking
Engraving is the oldest and most common of the intaglio techniques. Lines are cut into a metal plate using a tool called burin or graver. After the process of incising lines has been finished, the plate is inked. Then the surface of the plate is cleaned and only the ink in the incised lines is left. A dampened paper is put on the plate. With the paper being pressed firmly against the plate, it absorbs the ink left in the lines. For etchings the plate is first covered with an acid-resistant wax or resin ground. Then the image is incised into the wax or resin layer with an etching needle. Finally the plate is dipped into acid. The acid bites into the exposed lines where the wax or resin was removed. These acid-bitten areas hold the ink. It is one of the very old techniques dating back to the fourteenth century when it was used to apply decorations on armor. Rembrandt in the middle of the seventeenth century pushed the etching technique to new heights.
Watch how a great artist of our time, Carlos Monsalve creates his etchings in his own studio
Lithography - Planographic Printmaking
The name comes from the Greek word lithos which means stone. The technique is based on the fact, that water and grease do not like each other. The design is drawn on a special, flat stone (limestone) or on a metal plate with a greasy water-repellant substance (greased crayon or a greasy ink called tusche). Then the stone was dampened with water and inked. The ink is absorbed by the greasy parts only. To enhance this effect, the plate can be treated with a chemical fluid after drawing the image. Afterwards a print can be produced by putting the plate in a press. Like for the woodcut, several plates - one for each color - are used to produce a color lithograph print.
Watch how Carlos Monsalve, a great artist printmaker, creates his lithograph in his own studio
Woodcut, wood engraving, linocut - Relief Printmaking
Woodcut is the oldest method of printmaking. A fine example are Japanese woodcut prints. For woodcuts the design is drawn on a wooden board. Then everything that shall remain unpainted, is cut away with the use of a knife or a tool called gouge. Next the board is covered with the ink/paint. The final print is produced by pressing the paper firmly against the block - using a roller or some kind of a press. To achieve prints in several colors, several boards were used - one for each color. Albrecht Dürer was an outstanding master of this technique.
Watch the demonstration about creating woodcuts (The Metropolitan Museum)
The Linocut is based on the same technique as the woodcut. Because of the softer material of the linoleum, a linocut is easier to produce than a woodcut. Picasso used this technique and developed it into his very own style: He produced multi-color prints by not using several linoleum plates, but by cutting away more and more from one plate. At the end, the process could not be reproduced because the original plate was gone.