The term intaglio comes from the Italian word intagliare, meaning “to incise.” In this technique, acid or a pointed tool is used to incise the composition into a metal plate, usually made of copper, but sometimes of steel, iron or zinc. After the image has been drawn, the plate is covered with ink, and then wiped so that only the incised areas contain ink. The pressure of the press forces the paper into the incisions where they pick up the ink, resulting in the raised character of the lines on the impression. Because often the sheet of paper is larger than the plate, an indentation of the plate edges, or platemark, appears around the edges of the image area. The different types of intaglio prints are distinguished by the technique used: etching, aquatint, and photogravure are made using acid to corrode the metal plate, while engraving, drypoint, and mezzotint are made using a sharp tool to incise, or scratch, the surface of the plate. Often several different intaglio techniques are used in the same print to achieve variations in contrast and tone.
In this method of printing the ink is neither pressed down into the paper nor raised above its surface, but lies exclusively on the plane of the paper. This means that with planographic printing the printed and non-printed areas on the surface of the print exist on the same plane. Planographic techniques include: lithography, serigraphy, pochoir, monoprints, monotypes, screenprints, digital prints, and counterproofs
Relief prints are characterized by bold contrasts of dark and light. In this technique the artist first sketches a composition on a hard, flat surface such as a wood or linoleum block; then the parts of the image that are not to receive ink are carved away from the surface, leaving only the composition visible on the top surface of the matrix. Ink is then applied to this raised surface with a roller. The raised image on the block is transferred to paper with a mechanical press or by pressing the block into the paper by hand. Since the areas of the block that were cut-away did not receive ink, they appear white in the printed image. The inked areas are slightly impressed into the surface of the paper from the force of the press and so appear indented into the paper. The primary relief techniques are woodcut, wood engraving and linocut.