Glossary
[Direct Incision] Printing
A design made using a matrix of wood (xylography), metal (calcography), or stone (lithography) and a press. This technology emerged during the Renaissance and was used to disseminate ideas and imagery of the period by pressing sheets or foils against the matrix to transfer the image. Printing is a form of direct incision, meaning that the artist manually carves images into the matrix with different instruments.
Relief Printing / Woodcut
Woodcut art involves transferring a drawing on paper onto the matrix of another material. The design would then be engraved as a wood relief. Renaissance woodcutters typically used delicate knives , boxcutters, and gouges to cut into pear, cherry, or boxwood. This direct incision work was often rough and harsh--but its masters achieved surprisingly fluid forms in wood. These prints may be produced from multiple woodblocks and more than one color of ink. It is a process that requires careful attention to the line work and the registration (the even positioning of the block or image on the paper) of each print as it is pulled.
The Process: The relief process of woodcut consists of carving into a flat printing surface, usually wood or linoleum, using various tools including chisels and knives. The process begins with the preparation of the surface. In the case of wood, the block is seasoned to prevent warping and cracking by reducing moisture content, and in the case of linoleum, the surface is degreased to ensure an even layer of ink before printing. Next, the desired design can either be drawn directly onto the surface, transferred from a sheet of paper directly onto the surface, or a sketch can be pasted onto it. Once on the block, the design can be carved. The areas of the printing surface that are cut away will not receive ink and will appear as the color of the paper. All uncut material on the flat surface will print as the color of the ink- typically meaning that the artists will cut the shapes around the intended image. After completing this step, the surface is covered in an even layer of ink using a roller. The block is printed either by hand, using a baren or wooden spoon, to apply pressure to the back of the paper once its placed on the block, or by placing a piece of paper on top of the block and putting it through a rolling press.
Intaglio Printing / Engraving
A design made on a metal matrix under a mixture of wax, bitumen, and putty. The artist applies to design with this combination, which is resistant to acid and instead corrodes the metal. The design may be thus applied with a freer hand, as if drawing with a pen--rather than a burin of relief painting that one must press into the material.
The Process: An engraving is created by cutting lines into a metal plate (usually copper) to form channels that can hold ink. The process begins with preparing the metal plate by polishing it to remove any imperfections in the surface. Next, the design is created by incising the plate with a burin, a sharp tool made of a wooden handle with a steel shaft ending in a beveled diamond-shaped tip. Driving the burin into the metal printing surface to create straight lines and, by holding the burin stationary and rotating the plate to create curves, results in recessed grooves that hold ink. Different sized burins along with varying amounts of pressure can create different sized lines. Once the design has been cut, ink is spread evenly across the surface of the plate and any excess ink is removed in much the same way as an etching.The engraving is printed by placing a damp piece of paper on top of the metal plate (ink side up), followed by printing blankets,and running it through the press
Intaglio Printing / Etching
To produce an etching, the artist heats the metal slab covered in a mixture of wax, bitumen, and putty, and then carves into the plate. The entire matrix is then submerged in nitric acid and the line etches lines (exposed to the acid) are bitten deeper into the metal plate. The etching process was perfected by Rembrandt.
The Process: An etching uses acid to incise lines and areas on a metal plate (typically copper or zinc) creating a design that can be printed. The process begins with the preparation of the metal plate in which the plate is polished and covered with an acid resistant ground usually made of asphaltum and beeswax. Next, the artist uses an etching needle to scratch their image into the ground exposing the metal underneath. Once the design is finished, the plate is dipped in acid where the acid eats at the exposed metal creating recesses to hold ink. This step of dipping the plate into acid is repeated until it reaches its desired state as different amounts of acid exposure can help to create tonalities in the print by creating varying depths of bite in the plate. The deeper the bite, the darker the line or value. After the desired state has been achieved, the ground is removed with a solvent and the plate is ready for printing. Etching ink is spread across the entire plate, the artist than buffs the plate with tarlatans (a cheesecloth permeated with starch) to remove excess ink off the surface leaving the ink in the etched lines. Once the plate has been wiped, the plate is placed on the bed of a rolling printing press (ink side up) and it is covered with a damp sheet of paper followed by printing blankets. The plate is drawn through the press, printing the plate’s image onto the damp paper.
Intaglio Printing / Aquatint
The artist covers the slab with small grains of bitumen, not unlike spray paint. The slab is then heated and submerged in acid. The longer the slab remains in acid, the deeper and thus darker the grooves and lines are. Typically, it is left in for 30 seconds to 5 minutes. It emerges with a grained, dotted effect--an effect similar to watercolor. Aquatint was perfected and popularized by Fransisco Goya.
Planographic Printing / Lithography
This form of printing involves creating a smooth stone surface with a design peeled off from the background and formed with different layers of ink.
The Process: The planographic printmaking process of lithography is created by drawing a design on either a stone or a metal plate and affixing the design through a chemical reaction. First, the design is drawn directly onto the printing surface using an oil-based crayon or liquid oil based materials. After the design has been drawn, powdered rosin is rubbed onto the surface followed by a layer of powdered talc, and finished by etching the stone or plate with acid diluted in a gum arabic solution. A chemical reaction occurs between the gum arabic solution and the stone or metal plate, affixing the design, making the drawn areas attracted to grease and the non-drawn areas attracted to water. The original drawing materials are wiped away with lithotine (a solvent), and a layer of asphaltum is buffed on the surface to provide a base for inking. Prior to inking the surface,it is dampened with water. Due to the etching process, the water is only absorbed by the blank areas and the ink only adheres to the greasy area. The stone or plate is placed (ink side up)on a lithographic press and a sheet of paper is laid on top. The printing surface and paper are covered with a tympan (packing material, typically paper) with a board, and then put through the press.