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Intaglio Printing

Of the four basic methods of printmaking... the other methods being woodcuts, lithographs and serigraphs...intaglio printing has lent itself to the greatest number of variables. The process of intaglio, incised or copper plate printing, uses a principle opposite to that of relief printing. The image to be printed is sunk into the printing surface and filled with a greasy printer's ink. Then the surface is carefully wiped clean so that the ink remains only in the incised design. The great pressure required to pick up the ink in the intaglio printing leaves a visible plate mark within the margin of the uncompressed paper.

All of the techniques listed below are basically similar. They vary only in the manner in which the lines to delineate the image are cut into the printing surface.

Engraving

The design is cut into a hard surface, usually metal, with a sharp tool called a burin. After inking, the plate is wiped clean with a scraper or burnishing tool to polish the rough edges. The ink remains only in the furrow left by the burin.

Etching

Instead of cutting directly onto the plate, the artist covers the plate with acid-resistant ground and then draws on the plate with special sharp tools to remove the ground where the design is to be. The plate is then immersed in an acid bath which bites into the plate where the protective covering has been removed. By leaving different areas exposed to the acid for varying lengths of time, the quality of the bitten can be controlled. The finished plate is then printed as an engraved plate would be. This process makes possible a freer and more fluid drawing, as well as other effects not easily obtained in engraving or drypoint. The flowing lines in the etchings of Whistler and Rembrandt were achieved by this process.

Drypoint

The artist works directly on the copper or zinc plate with a sharp steel or gemstone needle which leaves two burrs of metal, one on either side of the scratched line. The depth of the line is controlled by the artist's muscle and experience. It is the ink caught in the burrs that forms the design and not the ink in the slight furrow which contains the design. Since the burrs wear off rapidly under the pressure of the printing press, only a very limited number of copies can be made from the design before the intended effect is lost, resulting in print edition sizes in the single figures.

Aquatint

Instead of lines being bitten by the acid bath, whole areas are exposed to the acid. The area is first prepared with a resin, usually in a powdered form, which is dusted on an area heated from below the plate to make it adhere. The plate is then given an acid bath to bite the tiny areas not covered by the granulated resin. The final effect is an image on a finely pebbled background. Most often this technique is used in combination with engraving or etching; however, there are examples of pure aquatint.