There are many printing methods. Each of them, except stenciling and offset printing, has a reversal in the process. There are four categories of printing: relief printing, intaglio, planographic, and stencil processes.
In relief: linocut, woodcut, or wood engraving, the surface of the die is cut away leaving raised areas where ink will transfer to the paper by direct pressure. The artist is carving the negative. With linocut, a stamp is carved in a piece of linoleum using specialized tools such as knives, gouges, and v-tools. The ink is rolled onto the piece of linoleum and direct pressure transfers the ink to the medium. Woodcut is similar to linocut, the image is carved out of side-grain wood. Style and surface quality differ. Wood grain can be seen in the image if correctly inked. In the wood engraving process, carving is done on the end grain, the much harder side of the wood. This allows for a higher detailed image to be engraved. Monotone prints can exercise the subtle effects of this technique.
Intaglio printing includes drypoint, mezzotint, and etching. The etched or engraved surface traps the ink and is transferred to the paper by direct pressure. The original raised surface does not print. The artist is etching the positive.
Drypoint is “drawing positively in black line and tone.” A sharp needle is used to apply pressure to a flat piece of metal, typically copper or zinc. This creates a valley or score that will accept ink. The printing process slowly wears away the burrs, so typically the first print will produce the sharpest, most crisp lines.
Mezzotint is “burnishing whites out of dark texture.” This process starts with roughening the surface of the copper plate with a mezzotint rocker. The rocker is worked evenly across the plate in several directions. The coarser the rocker, the denser the black marks will be. The ink will attach on this newly roughened surface, so the whites or grays are burnished away using a burnisher or curved scraper. The final product has a velvety texture appearing to be worked with chalk or charcoal.
Etching is done using a chemical to corrode, bite, away parts of the copper or zinc plate. The plate must have beveled edges and be free of any oils, greases, or any other contaminant. A hard ground is applied to the surface of the plate. It is slowly spread on the plate using a hard roller and a hotplate. The ground resists the etching of the chemicals. The etching needle is used to draw on the plate, carefully scraping away the ground paying close attention not to scratch the metal surface. Other tools used are pens, dental drill bits, and other random scraping tools. The plate is stopped-out by applying a stopping-out varnish to the areas where there is no drawing. This ensures that the acid will only bite the drawn areas. After the plate has completed it’s biting, the acid bath is rinsed off with water. The stopping-out varnish is removed with mineral spirits leaving only the etching on the plate.
All intaglio printing processes are the same. The paper is soaked in water to help the ink absorb into the paper. The ink is smoothed into the plate and the excess is gently wiped clean, leaving the ink in the etchings. Multiple colors of inks can be applied to the etching by daubing the desired colors, somewhat like painting. Paper is placed on the plate and put through the press. The paper is pressed into these etchings picking up the ink and slightly embossing the media.
Planographic printing includes lithography (direct pressure or offsetting) and monoprint. The printing and the non-printing surface are at the same level. With offset printing the image on the plate is not reversed because it is transferred to an intermediary surface and then transferred to the media. In effect a double reversal takes place.
Monoprint uses a unique image obtained by applying ink to a flat surface and giving direct pressure to transfer the ink to the media. Types of surfaces are glass, plastic, metal, stone, wood, and composition board. Ink is applied to the surface using brushes, rollers, knives, rags, pretty much any method of transfer or removal is acceptable. This process is similar to painting, drawing, and erasing. How much ink and pressure are applied will affect the tone and texture of the print. More pressure will make the colors stronger and the textures more detailed. Heavy use of ink will produce a strong color that may bleed, while the inverse will show the texture of the paper and a lighter color.
The lithography process is worked by applying grease marks to the plate, to which ink is attracted. The plate is prepared by applying a counter-etch solution and rinsing it off. The image is drawn on the plate using lithographic crayons or pencils, and lithographic ink with brushes, sponges, or rags. The drawing is left to dry and then dusted with talc and powdered resin. A liquid-etch solution is brushed over the plate and rinsed off to fix the image. A second processing involves applying a layer of gum arabic on the plate, allowing it to dry and using mineral spirits to clean it away leaving only a greasy shadow on the plate. Asphaltum is applied, allowed to dry, and washed off with water to strengthen the textures. Gum arabic is again applied, left to dry, and removed. Ink is rolled onto the surface of the plate and removed by hand where residue builds up on the non-printing area and allowed to dry completely. Next the ink is transferred to the press roller by moving the roller back and forth on the plate. Finally the paper is placed on the press and the roller is rolled across the paper, transferring the ink.
With stencil printing, the medium is blocked from ink being applied by pressure from a roller or squeegee. The remaining stencil creates the negative space. Screen printing or serigraphy is an example of this style.
