Aquatint (intaglio) - This etching technique achieves subtle gradations of tone through a very fine network of tiny islands of white where the plate is protected from the acid. This effect is obtained by having fine particles of acid resisting material on the plate. Materials used include resin, asphalt bitumen and pitch. These can be dusted on as a dry powder after which time the plate is heated to melt the material which sticks to the copper. Alternatively, the material can be dissolved in mineral spirits and poured on the plate. As the spirits evaporate, a thin film of resin remains. When it dries it splits, much like a mud flat. This exposes the copper to the effects of the acid. Coarser grains can be used to create textural effects in the image. The final result is a softened subtle toning that enhances the artist’s ability to create textures.
Drypoint (intaglio) - In drypoint an etching needle is used directly on the copper plate. In contrast to the engraving burin, which removes the excess metal leaving only the groove behind, the drypoint needle pushes metal up on each side of the groove. These ridges of metal (called burrs) retain more ink increasing the contrast of the image. Because these burrs are fragile, only a limited number of prints can be made from a plate before the image deteriorates due to loss of the burrs.
Engraving (intaglio) - In engraving, a metal plate (usually copper) is used as the blank ‘canvas’. A tool called a burin is used to cut directly into metal. A deeper cut holds more ink and results in a darker line, while shallower cuts create a lighter part of the image. Shading can be achieved by cross hatching, or using a roller tool with multiple points to create stippling. Engraving was frequently used for architectural representation. Reproductions of famous works of art were also created by engraving and used as illustrations. You have almost certainly seen scenes of Europe or America printed from engraved steel plates. Steel was used for these images because it was much more durable so more copies could be printed. Engraving is only infrequently used for fine art purposes.
Etching (intaglio) - The first dated etching is from 1513. The etching process uses acid in place of the burin. A copper plate is covered with a thin wax coating, called the ‘ground’. The artist uses a needle to sketch the image. The needle opens the wax exposing the copper. The copper plate is then immersed in an acid bath. The acid eats into the areas where the wax has been removed. The longer theplate is exposed to the acid, the deeper the groove resulting in darker lines when printed. Varying the darkness of the line can be accomplished in two ways. Stopping out involves creating the entire image in the wax. The plate is immersed then removed and rinsed. Varnish is applied to the areas that are to be lighter, and then the plate is again immersed in the acid. This process can be repeated several times. It is challenging to achieve subtlety with this technique. An alternative is to build the image in stages. The darkest lines are etched into the plate first, and the plate is immersed. After the plate is removed, new lines are etched and the process is repeated as many times as necessary. This is called the Cruikshank technique, after George Cruikshank who developed this technique in the early 19th century. This technique allows a much wider range of tonal expression. A final way to affect the tone of the final image is to leave a fine film of ink on some parts of the plate. This method is called retroussage. A feather or fine cloth is used to tease ink out of the grooves and spread it on selected areas of the plate. This toning enhances the image and makes the scene more dramatic. Several other techniques can be used to create the etched image. See Aquatint, Drypoint, Mezzotint.
Lithography (Planographic) - Lithography was discovered in Germany by Aloys Senefelder in 1798. A finely polished stone was used initially (lithography literally translates as stone writing). The simplest technique is to use a pen with a very greasy ink. The artist then draws the image directly on the stone. The resulting image looks very much like a pen and ink drawing. More commonly a lithographic chalk or crayon is used. Because the chalk is soft, variable pressure can force chalk into the fine texture of the stone creating a darker line. This allows a greater range of tone. One of the interesting aspects of lithography was that the only suitable stone was a specific type of limestone from Bavaria. This stone is no longer available; although older stones can be reused by grinding the stone down to remove the previous image. Most lithography is done on either zinc or aluminum plates roughened to accept ink since they are not porous like limestone.
Mezzotint (intaglio) - This etching/engraving technique was invented in the mid-17th century to enhance the artist’s ability to create the middle tones to the image (mezzotint literally translates as half tint). The plate is prepared by using a rocker to create a series of dotted lines scored in the copper plate. The artist then works using a scraper and burnisher to remove the burr from all portions of the plate that are not to be printed in a solid color. The copper can be worked all the way back to a shiny copper surface that doesn’t hold any ink. This gives the artist an incredible ability to create a wide range of tones. This technique is very labor intensive and fell out of favor, although some contemporary printmakers are returning to this technique as the image quality is unique and superb.
Offset Lithograph (planographic) - This term is typically applied to photomechanical reproductions. Examination of this type of print using a magnifying glass generally reveals a regular pattern of colored dots (called Ben Day dots). There are other photomechanical reproduction techniques that date to the late 19th and early 20th century that show irregular dot patterns (called stipples). Examples include chromolithographs and collotypes. While not original prints, some of these early prints are very desirable.
Photogravure (or gravure) (intaglio) - This technique was the first to transfer photographic images onto a copper plate to create an intaglio image that could be printed in multiple copies. It emerged in the 1890s and revolutionized the printing industry. High quality photogravures can be difficult to distinguish from original intaglio prints.
Screenprint/Silkscreen (planographic) - Screenprinting is the newest print technique having been invented in the early 20th century. Some attribute its use as a fine art printing technique to Harry Shokler. The technique uses a screen of fine mesh (initially silk although more recently manmade materials such as terylene). The image is created either by cutting out stencils that sit on the mesh and block out transfer of the pigment to the paper, painting the mesh with an opaque material that hardens and prevents the paint from reaching the paper, or by drawing on the mesh with a greasy substance and printing with a thick water-based material in which case the grease repels the paint. This technique can also be used to do photographic transfers.
Serigraph (planographic) - Another term for screenprint.
Woodcut and Linocut (relief) - A woodblock is carved to create the printed image. The great Japanese ukiyo-e printmakers used fine polished end cuts to create extremely fine images of life in Japan. In the late 19th and 20th centuries, artists began to incorporate the grain of the wood to enhance the image. A linocut uses a piece of linoleum rather than a wood block. Metal plates have also been used. Woodcut printing generates bold images that are well suited to the strong graphic aesthetic of the early 20th century.
Wood engraving (relief) - While technically very similar to the woodcut, wood engraving uses a surface of polished end grain of extremely hard woods such as box or oak. This allows the artist to use engraving tools to create very fine images. This ink still lies on the surface of the block as opposed to metal engraving (which is an intaglio method). While this was primarily used to create images for publications such as Harper’s Weekly, artists such as Asa Cheffetz used this technique very effectively. Another variation of this technique is White-line wood engraving where the black image is defined by the white spaces. This technique was discovered and perfected by the Provincetown Artists Colony in the first part of the 20th century.