Abstract art 

Art that departs significantly from natural appearances. Forms are modified or changed to varying degrees in order to emphasize certain qualities or content. Recognizable references to original appearances may be slight. The term is also used to describe art that is nonrepresentational.

Artist Proof

An artist proof is one outside the regular edition, but printed at the same time or after the regular edition from the same plates without changes. By custom, the artist retains the A/Ps for his personal use or sale. Typically 10% of the total edition is designated A/P or in the case of a small edition, five graphics are usually so designated.

Aquatint

A print produced by the same technique as an etching, except that the areas between the etched lines are covered with a powdered resin that protects the surface from the biting process of the acid bath. The granular appearance that results in the print aims at approximating the effects and gray tonalities of a watercolour drawing.

Certificate of Authenticity

Certifies the authenticity of a piece in a certain edition.

Etching

The technique of reproducing a design by coating a metal plate with wax and drawing with a sharp instrument called a stylus through teh wax down to the metal. The plate is put in an acid bath, which eats away the incised lines: it is then heated to dissolve the wax and finally inked and printed on paper. The resulting print is called the etching.

Gauche

The technique of applying opaque watercolour to paper, also a work of art so produced.The usual gauche painting displays light reflecting brilliance quite different from the luminosity of transparent watercolours.

Lithography

In the graphic arts, a method of printing from a prepared flat stone, metal or plastic plate, invented in the late Eighteenth century. A drawing is made on the stone or plate with a greasy crayon or tusche, and then washed with water. When ink is applied it sticks to the greasy drawing but runs off (or resisted by) the wet surface, allowing a print, a lithograph, to be made from the drawing. The artist, or other print maker under the artists supervision, then covers the plate with a sheet of paper and runs both through a press under light pressure. For colour lithography, sperate drawings are made for each colour.

Screenprint

(Also referred to as Silkscreen or Serigraph) is a colour stencil printing process in which a special paint is forced  through a fine screen on to the paper beneath. Areas which do not print are blocked with photo sensitive emulsion that has been exposed with high intensity arc lights. A squeegee is pulled from back to front, producing a direct transfer of the image from screen to paper. Aseperate stencil is required for each colour, and 100 colours or more may be necessary to acheive the desired effect. A screenprint differs from other graphics in that its colour is made up of paint films rather than posting ink stains. This technique is extremely verstile, and can create effects similar to oil colour, transparent washes as well as gouche and pastel.