Aquatint produces tonal effects similar to watercolour wash. Powdered resin is made to adhere to a metal plate; the metal that remains exposed around the tiny drops of resin is bitten in the acid bath, creating a pitted, grainy surface. These textured areas hold a thin layer of ink which prints as an area of tone. The longer the plate is left in the acid, the deeper the texture will be bitten and the darker it will print.Carborundum is similar to aquatint in that painterly, tonal effects can be achieved. A paste is made using grit (finely ground silicon carbide particles) and strong glue. The image is then painted or drawn with this paste onto the plate (copper, aluminium or Perspex) and allowed to dry. Inks are then applied to the plate and it is wiped and printed like other forms of intaglio print.
Collograph takes its name from the French colle, meaning glue, and the Greek graphos, meaning drawing. Essentially, it is a print from a collage. The plate is built up using a collage process which combines materials as diverse as cardboard, fabric, gesso, glue and found objects. Collographs do not necessarily have to be in colour. They can be printed blind, where an un-inked plate is put through the printing press to produce an embossed effect on the sheet.
Drypoint prints are created by scratching directly into the metal plate using a sharp pointed tool or needle, which is held like a pencil. As the needle scratches the copper, it throws up a ridge of metal or burr on both sides of the scratched line. The burr creates a soft and velvety line when printed.
Etching is an intaglio technique in which a print is taken from a sheet of metal, usually copper, zinc or steel, into which the drawing has been bitten with acid. It involves coating a metal plate with a thin acid resistant layer or ground, usually a wax based resin. Using a sharp tool, a drawing is scratched into this layer leaving the metal exposed. The plate is then immersed in a bath of acid which ÔbitesÕ or etches away the metal in the areas exposed by the drawing. Once the lines have been etched to a sufficient depth the ground is cleaned off. Ink is rubbed into the lines of the design and the surface is wiped clean. A sheet of dampened paper is placed over the plate and it is then fed through a printing press under great pressure. This causes the ink to be pulled out of the incised lines onto the paper and creates the platemark.
Flexograph, often abbreviated to flexo, is a method of surface printing most commonly used for packaging. A flexo print is achieved by creating a mirrored master of the required image as a 3D relief in a rubber or polymer material. Ink is deposited on the surface of the printing plate (or printing cylinder) using an anilox roll. The print surface then rotates, contacting the print material which transfers the ink.
GiclŽe (digital print) is a French word which means ÔsquirtÕ or ÔspurtÕ. GiclŽe digital printing is a relatively new process which has become highly regarded by collectors, galleries and museums. It combines new digital technologies with ink-jet printing techniques. Unlike other fine art prints, a GiclŽe print is normally produced one at a time on an as-needed basis.
Lithograph literally means Ôstone drawingÕ. When lithography was invented in Germany in the late 18th century, the print was created by drawing on a special type of smooth limestone, although a metal surface is sometimes used today. It is a planographic or surface process which is based on the fact that grease and water repel each other. Using a greasy medium (a crayon) a drawing is made on the surface of the stone which is dampened with water. Greasy printing ink is then rolled over the surface. The ink adheres to the drawing but is repelled by the damp paper. Any medium, so long as it is oil based, can be used to draw the image and this explains why lithographs can have so many different appearances and are sometimes mistaken for original drawings.
Mezzotint is a tonal process characterized by soft areas of light and dark. Unlike other intaglio processes no acid is used and the plate is worked manually from dark to light. The whole plate is systematically roughened using a serrated chisel like tool called a rocker or roulette. If printed at this stage it would be a rich uniform black. The image is created by smoothing out or burnishing areas of texture to achieve modulated tones. The areas partially flattened will produce greys, and areas completely flattened render whites because the now smooth metal no longer retains ink.
Screenprint is created by one of the few printmaking processes in which pulling the print does not result in a reversed image. It is a stencil technique in which the stencil is painted, adhered, or exposed to a screen of mesh fabric stretched tightly over a frame. Silk is usually used (the process is also known as silkscreen or seriagraphy), but sometimes cotton, nylon or a metal mesh forms the screen. Ink is forced through the mesh with a flexible squeegee (rubber blade).
Spitbite aquatint is an intaglio process which involves painting strong acid directly onto the aquatint ground of a prepared plate. Depending upon the time the acid is left on the plate, light to dark tones can be achieved. To control the acid application various solutions can be used. Traditionally, a clean brush was coated with saliva, dipped into nitric acid and brushed onto the ground, hence the term ÔspitbiteÕ.