ARTIST'S PROOF - The artist normally makes several 'proofs' of the finished print outwith the numbered edition. Works from the numbered edition are available for general sale while the artist or publisher may retain the artist's proof copies for their own use.
BAT - Stands for Bon a Tirer (good for printing), a French term which means that the final proofed print has been checked and approved by the artist and that the printers can edition the print, using the BAT as a guide.
HORS DE COMMERCE French term meaning that this copy of a print or book is intended for display purposes only and is not for sale.
ETCHING - A metal plate, normally copper, zinc or steel, is covered with an acid-resistant layer of rosin, a type of resin, mixed with wax (this is called the 'ground'). With a sharp point the artist draws through this ground, but not into the metal plate. The plate is placed in an acid bath and the acid bites into the metal plate where the drawn lines have exposed it. (If the plate is left in the acid for a long time, the technique is known as deep-bite etching). The waxy ground is cleaned off and the plate is covered in ink, then wiped clean, so that the ink is retained only in the etched lines. The plate can then be printed through an etching press. The strength of the etched lines depends on the length of time the plate is left in the acid bath.
ENGRAVING The engraver pushes a lozenge-shaped chisel called a burin through the plate (either metal or wood), leaving a clean-edged incision. This technique requires a great deal of control and is not suited to spontaneous mark-making.
MONOPRINT This is a single, unique print, made by the artist with this intention. A monoprint can be produced by any printing technique screenprint, etching and lithography but it is issued only as a single print, and is not editioned.
SCREENPRINT Also known as silkscreen. In its simplest form, this is a technique by which the artist blocks out sections of a fine, woven screen, (formerly made of silk), which is stretched over a frame. With a squeegee, ink is pressed evenly through the screen on to a sheet of paper beneath. Only the areas of the screen not blocked out will be printed. Screenprints bearing several colours are made by printing through several different screens, one screen for each colour. Normally an artist will paint on to transparent sheets of film (the same size as the desired print) with a special photo-opaque paint through which light does not penetrate. The artist will use as many of these transparent sheets (separations) as the numbers of colours required in the print, and each sheet must be aligned very carefully with the others. The films are transferred on to the silkscreens via a light-sensitive process: only the areas which are painted by the artist will be blocked out and will not allow ink through. Screenprinting became widely used in Europe only from the late 1940s.
PHOTOGRAVURE This technique was common in the late nineteenth century but is rarely used today. Essentially it means transferring a photographic image on to an etching plate. A photograph is taken of a painting or other image, then the photograph is transferred on to a large sheet of bromide film.
pFrom these bromides large transparencies can be made, to the scale of the desired print. The transparency is exposed to a sensitised sheet of gelatine and is then transferred on to a copper plate with a squeegee. The image is etched through the gelatine film on to the copper plate in a series of ferric baths.
AQUATINT Aquatint is a means of producing tone rather than line. The artist covers the etching plate with grains of rosin. When the plate is immersed in acid the liquid eats into the metal around each grain, leaving a tiny etched ring around each. The acid can be applied over the whole plate to give an even tone or painted on by hand to create the effect of brushstrokes.