Intaglio Printing


Aquatint is an intaglio printmaking technique that is designed to create a range of tones and shades rather than lines. Fine particles of acid-resistant material known as rosin are attached to a printing plate by heating. The acid eats into the metal around the particles to produce a granular pattern of tiny dots. The plate is then immersed in an acid bath and the longer the acid is allowed to etch away at the surface, the more profound the indentions and darker the hues of the final print. Shapes are defined by painting on an acid-resistant laquer to prevent surrounding areas from being ‘bitten’ by the acid. The recesses are then filled with ink and the plate is pressed onto a dampened sheet of paper, where the ink transfers onto it to create the finished artwork. There are variant methods of the process including soap ground aquatint, spit bite aquatint, sugar lift aquatint, water bite aquatint and aquatint reversal.



Drypoint is an intaglio printmaking technique in which the design is scratched directly into a metal plate with a diamond-pointed instrument. Drypoint is usually done on copper plates as the softer metal lends itself to this technique. The lines are characteristically fuzzy with velvety edges caused by the burr, a rough ridge of metal thrown up on each side of the furrow by the drypoint instrument. Once the drawing is complete, an ink-soaked cloth is used to fill the crevices with ink, and the remaining flat surface is wiped down to ensure it sits only in the areas where the etching occurred. Damp paper is placed on the plate and run through a press, picking up the ink from the incised lines and the burr. In principle, the method is practically identical to engraving. The difference is in the use of tools, and that the raised ridge along the furrow is not scraped or filed away as in engraving. Owing to the delicate nature of the burr, drypoint is usually made in small editions, stopping before the burr is crushed by the pressure of the intaglio press. Drypoint is often combined with other intaglio techniques, such as etching.


Like etching and aquatint, engraving is a printmaking technique that involves making incisions into a metal plate which retain the ink and form the printed image. The design is manually incised into an engraving plate using a burin, an engraving tool like a very fine chisel with a bevelled tip. The burin makes incisions into the metal at various angles and with varying pressure, which dictates the quantity of ink the line can hold. Engraved images are comprised of a multitude of crisp, fine lines; and tone and shading are traditionally rendered by multiple parallel lines or cross-hatching. Engraving is one of the oldest techniques in printmaking and the earliest known dated engraving is from 1446. 



Etching is an intaglio printmaking process in which lines or areas are incised using acid into a metal plate. The plate, traditionally copper but now usually zinc, is prepared with an acid-resistant wax, called the etching ground. Incisions are then made through the ground with an etching needle to expose the metal. There are many ways to etch out the areas from the flat plate surface, with the most common being drypoint and aquatint. The plate is then immersed in an acid bath, known as the mordant, which eats away at the areas of the plate unprotected by the ground, forming a pattern of recessed lines. The characteristics of the marks produced depend on the tool used to draw the image, the type of ground coating the plate and the length of time the plate is etched in the acid bath. The remaining ground is then cleaned off the plate before being inked. The plate is then put through a high-pressure printing press together with a moist sheet of paper. The paper picks up the ink from the etched lines and the design is transferred. This process can be repeated many times.


Mezzotint is a printing technique developed in the 17th century which is akin to drypoint. It allows for the creation of prints with soft gradations of tone as well as rich, opaque blacks. The process involves indenting the surface of a metal printing plate with a spiked metal tool called a rocker. The design is then created by scraping down and polishing areas of the plate using a burnishing tool. Ink is applied to the entire metal plate before being wiped clean. The small pits achieved in the roughening process however retain the ink, allowing for the creation of half tones when put in contact with paper through a printing press. The process requires great care as the mezzotint plate is particularly prone to wear during printing. The result is that the earliest impressions are the finest and print very dark with strong definition whereas later ones are noticeably fainter as the plate’s roughened surface deteriorates.



Photopolymer photogravure, or heliogravure, is a complex intaglio printing process that photographically transfers an image to a plate and then to the page. Similar to an etching process, it uses a copper plate covered with a light-sensitive gelatine tissue which is then exposed to the light from a photographic image. The plate is etched in differing depths in proportion to the tones of the picture, the gelatine hardening where the light falls and remaining soft where light doesn’t. This results in a highly defined intaglio plate that can be used to print the image onto paper using inks. The end result reproduces detailed continuous tones of the original photographic image.