Printing Processes continued

Printmaking Processes

An original print is an image on paper or similar material made by one or more of the processes described here. Each medium has a special, identifiable quality, but because more than one impression of each image is possible, "original" does not mean "unique." Prints are multiple originals. The development of printmaking was connected to the development of movable type and the printing press in the fifteenth century, although woodblock printing had been done on textiles since ancient times. If you are interested in the history of printmaking, click on this link.

In contemporary printmaking, artists frequently number their prints. The total number of prints made of one image is an edition. The number may appear on the print with the individual print number as a fraction such as 5/25 meaning that this particular print is number 5 of 25 prints made.

Prints in color require two or more blocks, plates, screens or stones, one for each color, printed sequentially on top of each other to produce the final work of art. This process is called registration.

Prints can be classified according to the type of surface used to make them. Those with raised printing surfaces are known as relief prints; woodcuts are the most common type of relief print. When the printing surface is below the surface of the plate, the print technique is classified as intaglio. There are several important intaglio techniques. Planographic and stencil methods are also used, and print from a surface that is at the same level as the non-printing surface.

Relief Prints

Woodcuts are made by cutting into the broad face of a plank of wood, usually with a knife (the linocut is made the same way, except that linoleum is substituted for wood). In working the block, the artist cuts away areas not meant to print. These cut away areas appear in the finished print as the white parts of the design while the ink adheres to the raised parts. This link will take you to a Web site that contains an entire textbook on Woodblock printing by Hiroshi Yoshida Or also try this site which offers a set of past to recent examples of European relief printing.

Wood engravings are made by engraving a block of end-grain, extremely hard wood. The block, being naturally much harder, enables the artist to engrave (rather than cut) a much finer line than is possible on the softer plank surface used for woodcut. Albrect Durer (15th c.) used this technique in many of his works.

Intaglio

Intaglio printing involves the use of a metal plate. In printing, the ink settles in the sunken areas and the smooth surface of the plate is wiped clean. The plate, in contact with damp paper, is passed through a roller press under pressure. The paper is forced into the sunken areas to receive the ink. The plate can be incised by one of several methods:

·  Engraving The design is cut into the plate by driving furrows with a tool called a burin. The careful control required by the cutting method results in a rather stiff, controlled style of image, with shading accomplished through the use of parallel lines, or "hatching." The plate is printed in the manner described above. Hogarth (18th c.) is an artist who often created engravings.

·  Etching A metal plate is coated with a material called a ground. The artist then draws his design on the ground with a sharp needle, that cuts through the ground to the metal below. When the plate is put in an acid bath, these exposed areas will be etched (or eaten away). This produces the sunken line which will receive the ink. The artist etches on the plate those parts which will appear in the finished print as black or colored areas. Since the ground is soft, the artist is able to work more freely than is possible with engraving, displaying a freer, more relaxed quality of line. The length of time the plate is left in the acid bath will affect the darkness and character of the lines. Rembrandt (17th c.) did many etchings; scroll down in this link to select examples.

·  Drypoint In this technique, the sunken lines are produced directly by diamond-hard tools pulled across the plate. The depth of line is controlled by the artist's muscle and experience. The method of cutting produces a ridge along the incisions, called burr. This gives the dry-point line the characteristically soft, velvety appearance absent in the clean edged lines of an engraving or etching.

·  Aquatint A copper plate is protected by a powdered ground that is melted onto the surface of the plate. It is acid resistant, but covers incompletely, resulting in a grainy surface texture. The longer the plate is left in the acid bath, the darker and heavier the texture will become. It is usually combined with a standard etching ground that permits lines and clear white areas as well. The final effect is an image on a fine pebbled background (imparted by the porous ground). Aquatint is usually employed in combination with line etching when subtle value gradations are desired.

For additional information and examples of intaglio printing, try this link.

Planographic Prints: Lithograph

Lithograph is a planographic technique in which the artist draws directly on a flat stone or specially prepared metal plate (usually with a greasy crayon). The stone is dampened with water, then inked. The ink clings to the greasy crayon marks, but not to the dampened areas. When a piece of paper is pressed against the stone, the ink on the greasy parts is transferred to it. Toulouse-Lautrec and Picasso (left) are among the artists shown who used this technique. For additional information about lithographs, go to this site on litho technique .

Stencil prints: Silk Screen

Silk screen is a type of stencil. This technique first came into use in the early 20th century. The artist prepares a tightly stretched screen, usually of silk, and blocks out areas not to be printed by filling up the mesh of the screen with a varnish-like substance (or any number of other materials which would block up the pores of the fabric). Paper is placed under the screen and ink forced through the still-open mesh onto the paper. This technique is also widely used on textiles, including the ever-popular T-shirt. Robert Rauschenberg and Andy Warhol are examples of artists that used silkscreen.

---

Original Graphic Arts Processes
Process	Relief	Intaglio	Planographic	Stencil
Common Name:	Woodcut, linocut, embossing	Engraving, drypoint, mezzotint, etching, aquatint	Lithograph	Serigraph (silkscreen)
What Area Prints:	Prints what is left of the original surface	Prints what is below the surface of the plate	Prints what is drawn on the surface	Prints open areas of the stencil
Type of Press:	Manual pressure or letter press	Etching press (clothes-wringer type)	Lith Press (sliding, scraping pressure)	Original Serigraphs are usually hand screened
Materials:	Wood or linoleum block or other film material	Copper, zinc, plastics, etc.	Limestone, zinc, aluminum plates, etc.	Silk, nylon, etc.
Basic Tools:	Knife, gouge, burin, etc.	Etching needles, burins, acids	Litho crayon, tusche, litho rubbing ink, etc.	Squeegee, screen, screen blocker (liquid, photosensitive block or film)

http://char.txa.cornell.edu/media/print/print.htm