SCREENPRINTING.
An ancient method of oriental printmaking which, considerably modified and ameliorated, has become one of the four most important methods of modern printing. Contemporary artists have made much use of it as a printmaking technique. The principle of screenprinting consists in applying stencils to a screen (constructed of silk or of some synthetic or metallic material), in such a way that when ink is applied it is prevented from passing through some parts while penetrating the rest of the screen, thereby printing an image on paper placed underneath. The screen is stretched across a frame and attached to a base in such a manner that it can readily move up and down, so that paper can be easily placed and removed as required. For each impression, the paper is placed against registration tabs to ensure that the printing is done in the correct position. The ink is poured over the masking at one end of the screen and when this has been lowered into position, the ink is scraped across the screen with the aid of a squeegee. The most important part of the process is the preparation of the screen. Stencils may be applied in a variety of ways, including the use of filling-in liquid, varnish or plastic film. A drawing can be made directly on the surface with a special ink which is removed in readiness for printing after the rest of the screen has been blocked out. A photographic stencil is made by initially sensitizing the screen.

SIGHT EDGE.
This refers to the work of art visible to the viewer. The actual edge of a painting or drawing may be concealed by the frame or mat.

SILKSCREEN.
The term usually used in America for screenprinting.

SIZING.
A substance added to paper to create a degree of water resistance.

SOFT-GROUND ETCHING.
One of the etching processes which aims to simulate the effects of a chalk or crayon drawing. The plate is initially covered with a soft ground. The drawing is made with a hard crayon on paper which has been pressed to the surface of the grounded plate; the ground adheres to the back of the paper where the crayon has left indentations in it, thereby creating an impression on the plate of the marks of the crayon. The paper with the attached ground is carefully removed and the plate is bitten. It is possible to reproduce any kind of texture with this method: textiles, rough papers, netting or leather can be pressed into a soft ground in a similar fashion.

SPLATTER.
A method of applying the ink in lithography. It is sprayed through a metal mesh onto the stone with the aid of a stiff brush. Areas which are to remain white or be very lightly splattered are protected with gum Arabic (staging out).

STATE.
The proofs taken while the artist is working on the plate, stone, etc. to check different stages of his progress are known as states; each one showing additional working constitutes a different state. The last one is said to be the definitive state (or proof).

STEEL-FACING.
A process consisting of depositing, by electrolysis, a very thin layer of iron onto a copper plate in order to reinforce it. Copper, the most commonly engraved metal, can become scratched and worn down through use. Furthermore, the wheels of the press tend to flatten out the indentations, removing the finest ones altogether, and rub away the idiosyncratic burr on plates engraved with the drypoint. In this respect steel-facing is an added protective and allows a greater number of impressions to be made while maintaining a constant quality. The steel-facing can be removed if reworking on the plate is required. Zinc must be faced with copper before being steel-faced. Chromium is sometimes used instead of steel, generally in photogravure, to strengthen the printing drums. It has the advantage of preventing oxidation (it is necessary to varnish or grease a steel-faced plate), and of producing a surface that facilitates wiping at the time of printing.

STEEL PLATES.
Iron plates are known to have been used before the sixteenth century and Durer made several etchings on this metal. Steel, made from a mixture of iron and a slightly larger proportion of carbon, did not become generally used until the end of the eighteenth century, and this was particularly in England. It can either be etched or engraved: frequently the indentations on the plate are first made with acid and then finished off with the burin. A steel plate has a particularly clean, sharp line that can be extremely fine; it also produces many more impressions than a copper plate. It is used in particular for book illustrations, stamps, book-plates, vignettes and greeting cards.

STENCIL.
1. Stencils are an essential part of screenprinting: they are attached to or incorporated with the screen to ensure that the ink passes through in the correct places. They can be made in many different forms, e.g. as a simple masking or covering stencil; as a "wash-out" stencil, which involves drawing the design on the screen in a greasy substance, then covering the whole screen with filler or gum, and finally dissolving the greasy image in turps, thereby forming a 11 positive " stencil; or as a photo-stencil, whereby photographic images are incorporated into the screen. 2. Stencils are also used for coloring prints by hand. Stencils of the areas to be colored are cut out in zinc or aluminium; the colors are dabbed on with a large brush (known as a " pompon " in French); they may be juxtaposed or superimposed over each other. The method was much used in the coloring of maps, topographical prints and devotional woodcuts. It is still used today for book illustration and on greeting cards. See: hand-colouring, registration.

SUBSTRATE.
The primary layer of material; can relate to a mount substance or the base material upon which a work of art is executed.

SUGAR-LIFT PROCESS.
A method of defining drawn areas on an intaglio plate. The necessary area is painted directly onto the metal surface with Indian ink in which sugar has been dissolved. This is covered with a stopping-out varnish and, when the latter has dried, submerged in water which causes the sugar mixture to swell, removing the varnish and exposing the metal at the parts where the drawing has been made.

SUITE.
A set of prints dealing with the same subject, or by the same artist, which are published as a whole. It can also refer to a series of prints taken apart from an illustrated book.

SULPHUR PRINT.
There are various ways in which sulphur is involved in printmaking. (1) A mixture of flowers of sulphur and olive oil can be applied directly to the surface of a metal plate to produce a tone similar to that of an aquatint. Some engravers spread the oil on first, and then apply the powdered sulphur. (2) A sulphur proof may be taken onto a sheet covered with sulphur, from an intaglio plate in which the incisions have been previously filled with lamp black.

SUPPORT.
In a painting, the physical structure that holds or carries the ground and paint film. Any material, such as fabric, wood, metal or paper, on which a work of art is executed, serving as a structural base.

SURFACE TONE.
If a plate is not completely wiped before printing, " surface tone " is created by the films of ink left on its surface. Selective wiping creates surface tone.