Lithographs can be printed on either dry or damp paper. The advantage of dampening is that it is possible to use less ink and less pressure, thus minimizing the risk of clogging the image.
To print, the printing paper is first placed on the stone, followed by a newsprint paper, and then a blotter. Last comes the tympan, a sheet of smooth, tough material that can withstand great pressure without stretching. After the bed is raised to printing position, grease is spread evenly in front of the scraping bar on the tympan to allow it to slide easily. Then the print is made.
The prints of the French artist Henri de Toulouse-Lautrec demonstrate that lithography offers endless possibilities in colour printing (see photograph). Because the effect of lithography is much more painterly than either woodcut or intaglio printing, it is natural that the strong preoccupation with pure colour in contemporary art has created a revival of interest in this medium. The planning and the principle of colour separation are similar to those for the colour woodcut or intaglio colour.
Jane Avril, lithograph poster by Henri de Toulouse-Lautrec, 1893; in the Toulouse-Lautrec Museum, Albi, France.SuperStock
Stencil processes
In stencilling, one of the simplest methods of duplication, the design is cut out of paper (or any other suitable thin, strong material) and is then printed by rubbing, rolling, or spraying paint through the cutout areas.
Silk screen is a sophisticated stencil process, developed about 1900 and first used mainly for advertising and display work. About 1950, fine artists started to use the process extensively, giving it the name serigraphy.
The silk-screen process got its name from the fine mesh silk that, when tacked to a wooden frame, serves as a support for a cut paper stencil. The stencil is glued to the silk. In the basic process, the open mesh of the silk lets the paint through, while the paper stencil blocks it out. A design can also be blocked out on the screen with glue or other suitable substance.
A common method of stencil preparation is to cut the stencil with a knife. In this method the artist can use commercially produced screen process printing plates or conventional stencil papers. For fine, accurate work, process plates, which consist of a film on a backing, are preferred. Areas to be printed are cut out of the film and peeled off, leaving the rest of the film on the backing paper. After the plate is attached to the screen, the backing paper is removed; thus, the screen is covered with film except in the printing areas. Process plates are available in different colours to make registering easier, and they are attached to the screen either by heat or by the use of a special solvent.
Another method that is quite common is the so-called tusche-and-glue method, which is similar to lift-ground aquatint etching. The design is painted on the screen with tusche and, when dry, the whole screen is covered with glue. When the glue dries, the design is washed out with either kerosene or turpentine. The tusche comes in liquid form for brushing or in solid crayon form. The use of the crayon results in screen prints that deceptively resemble lithographic prints.
Stencil plates can also be made photographically. These plates are made by placing a photographic positive on a photosensitized gelatin stencil plate in a vacuum printing frame. Exposure to light hardens the gelatin under the transparent areas but leaves the gelatin soft under the dark areas. In warm water the soft areas wash out. The stencil is attached to the screen in the same manner as other stencils.
To make a silk-screen print, the wooden frame holding the screen is hinged to a slightly larger wood board. The printing paper is placed on the board, under the screen. The consistency of the ink is important: it must be liquid enough to pass through the screen but not so liquid that it runs. The ink is pressed through the screen with the squeegee (a rubber blade, usually the same width as the screen, set in a wooden handle). Any number of colours can be used, a separate screen for each colour. Special techniques Monoprint (monotype)
A monoprint is a unique print. The artist paints on a surface such as metal, plastic, or glass and then transfers the wet design to paper, either by rubbing or with an etching press. The primary reason for making a monoprint is that, when the image is offset from the plate to the paper, the print achieves a separate quality and luminosity totally unlike a painting made directly on paper. In the 19th century, Edgar Degas did considerable experimentation with monoprints and produced a great number of superb ones. He often worked over the proofs with paint or pastel. There has been a strong revival of interest in this method. Cliché-verre
The method of printing known as cliché-verre was used by a few artists in the 19th century during the period when photography was a new and exciting invention. The cliché-verre method follows the principle of photography but does not have its tonal variations. The print was made by covering a piece of clear glass with an opaque pigment or emulsion; the design was then scratched through with a sharp etching needle or stylus. When the drawing was finished, the glass plate (negative) was placed on a photosensitized paper, exposed to light, and then developed. The result was a (positive) print with strong black-and-white contrasts. Some of the best cliché-verre prints were made by the French landscape painter Camille Corot. The cellocut
The cellocut method was named by its originator, U.S. printmaker Boris Margo, one of the first to experiment extensively with plastics.
In this method, liquid plastic that has been dissolved in acetone is poured onto a rigid support backing, such as fibreboard or cardboard. The solidified plastic can be textured, raised into relief, and worked with various tools. It can be engraved, scratched, sanded, and filed. The resulting plastic plate can be printed either as a relief or as an intaglio plate, or even both. It can be printed alone or in combination with other techniques. Thin layers of plastics can easily be placed on top of intaglio plates and printed together. Collagraphy
Like the metal graphic process, collagraphy is an additive method; the printing surface is built up. It is essentially an intaglio method, but it can be combined with relief printing. The printing surface is created by gluing various materials and textures to a support. Today, with the variety of new material available, the possibilities are limitless.
The support (plate) for collagraphy must be thin and strong. A porous material, such as cardboard, must be treated with a sealer. To build up a tough, durable printing surface, a strong adhesive such as polyvinyl acetate must be used.
Among the materials that can be used for tonal areas are sawdust, sand, carborundum, sandpaper, and ground walnut shells. For specific textures, materials such as tarlatan, laces, and crushed paper can be glued into the adhesive.
After the plate has been constructed, the surface is sealed. The sealer can be either brushed or sprayed on. Plastics are preferred because they are tough and are not dissolved by the solvents generally used to clean the plate.
The printing of collagraphs is essentially the same as for intaglio printing. Plaster print
Good proofs of an intaglio plate can be made by plaster casting, for fine plaster of paris will pick up the most delicate details. This method will produce a particularly attractive proof if the plate has deeply etched or engraved sections.
To make a plaster print, the plate is inked in the same manner as it would be for normal printing. The inked and wiped plate is placed face up on a glass plate, and a precut wood frame is placed around the plate to contain the plaster. After the plaster is poured, it is allowed to cool and set, after which the plate is gently removed. Process prints