Aquatint engraving
The aquatint engravings arose in the 18th century, due to the efforts of the artists to recreate in the engravings the effect of watercolors and gouache drawings. Among the artists who practiced this technique is the Spanish Goya, and its inventor must have been the Frenchman Jean-Baptiste Le Prince.
Aquatint is an intaglio process, similar to etching, that produces a print with an entirely different appearance. Large segments of the sheet are exposed to the acid, creating tonal zones rather than lines. To create an aquatint print, certain areas of the sheet are sprayed with resin and the sheet is heated so that the resin adheres. The sheet is then dipped in a mild acid which dissolves the surface in areas not covered by the resin. If the artist wants, once the aquatint engraving is finished, some areas to be darker than others, he will expose these to a longer action of the acid that will end up chipping them and thus they will retain the ink better. The aquatint method is difficult to control and is often used in combination with etching and drypoint engraving techniques.
History
The painter and engraver Jan van de Velde IV invented the aquatint technique in Amsterdam around 1650. Cartographer Pedro Pérez Burdett later presents his "secret" aquatint to England in the 1770s. In the United States, engraver José Pedro de Lemos popularized aquatints in art schools with his publications (1919-40), which simplified cumbersome techniques, and with traveling exhibitions of the award-winning prints of him.
Francisco de Goya is considered an expert in aquatint, and except for some of his images, in most of his images this technique is combined with line etching, with which he obtained the most expressive results from surprising simplicity. The tonal character of the images made this technique the ideal means of color recognition in the XIX century, as demonstrated by the images by George Baxter, which he combines with overprints from various woodcut blocks. At the end of the XIX century, the heliographic gravure technique was developed, which combines aquatint and photographic image, producing a distinguished by the combination of the photographic with the quality of the calcographic printing.
Technique
The most common procedure for aquatint is to sprinkle and melt rosin (or other materials) onto the surface of the plate, so that it functions as a dot reserve. Once fixed, it is subjected to the action of the mordant, which, depending on the times, will produce more or less dark tones. The appearance also depends on the thickness of the powder used and the density with which it is deposited on the plate: the higher the concentration of resin (in the same bite time) the effect will be clearer and vice versa, since there is more area of the metal protected.
The resin can be applied both in the resin box or with a sieve, it is important to highlight that to achieve uniform tones or deep blacks, it should be done using the former. Once applied, the corresponding reserves are made that will determine the different types of gray, either with varnish (or substitute) or with a greasy pencil (wax or lithographic) that will allow the creation of degraded tones.
Generally, resin and line work are usually accompanied. It is advisable, at the beginning of the process, to make the line first and then the stain. In successive state tests, it will be varnished again to continue the preparation of the drawing.
Sugar Aquatint
A derived technique is sugar aquatint. This technique involves positive drawing by mixing India ink and saturating it with sugar. The proportion of Chinese ink is 60% and that of sugar 40%. This mixture is applied with a brush to a plate prepared for engraving with resin. As the mixture is almost dry, a resistant varnish is applied and submerged in warm water. Sugar aquatint allows a more dynamic line, unlike the conventional technique.
Other soluble media for this technique are gouache, tempera, gum arabic and even condensed milk, the latter used by authors such as Joan Miró. Pablo Picasso used sugar aquatint, as he considered that "everything is more direct and at the same time more delicate".