Another of the intaglio printmaking methods, etching involved the application of an acid-resistant ‘ground’ (a waxy substance comprised of tar, asphaltum and pitches) to the surface of a metal plate. Through this, the lines of the illustration where scratched with an etching needle, so as to expose the bare metal. The whole was then dipped into a bath of acid, which ‘bit’ into the metal, dissolving the parts left exposed and leaving behind the incised lines not dissimilar to those of the engraver’s burin. It is a centuries-old method, believed to have been in practice since the 1490s, though the earliest dated work on copper has been attributed to Swiss goldsmith and printmaker, Urs Graf, in 1513. From its very beginnings the process was popular with painters. It allowed them to draw with a certain freedom, one typically associated with pen-and-ink drawing, not with line engraving in all its formality. Perhaps this is why it initially appealed to German Renaissance painter, Albrecht Dürer, for his etchings on iron appeared around this time too. Though he abandoned the method early on, returning to his favoured engraving, his artworks proved a constant source of inspiration for later engravers. One of the earliest works, a copy of Dürer’s ‘Virgin and child’, by the prolific 17th century Bohemian artist, Wenceslaus Hollar, dates from c1625. Hollar would go on to produce some 3,000 etchings across a variety of subjects, including: religion, heraldry, architecture, landscapes and portraits. Other great artists who tried their hand at etching include Italian painter, Giovanni Benedetto Castiglione and Rembrandt.
Over the years important technical advances have been made in etching materials and techniques. Though a variety of metals have been used, including iron (the earliest for printmaking), brass, zinc, steel and aluminium, it was copper that (by the 1520s) was deemed the way of the future. It was relatively soft, could easily be etched and ‘bitten in’ by acid, wiped clean and bitten in again. Developments in etching needles and etching-ground by Jacques Callot also began to appear in the 1600s. He offered etchers a needle with a slanting oval section at its end, which was capable of producing a swelling line similar to but less sharp than that created by the engraver’s burin. He also invented a recipe for etching-ground which was harder, more like a varnish than a wax, and enabled lines to be bitten more deeply by the acid. Perhaps most importantly, it minimised the risk of ‘foul-biting’ which occurred when the acid found its way through to the plate where it was not supposed to be, causing unsightly spots on the final print. These developments went some way toward simplifying what was quite a complex process, and yet it was still considerably easier than line engraving. Many artists were even able to etch their own plates; only a select few could actually engrave. Indeed, etching was very well received. People embraced the close resemblance of the print to the original artwork, possibly feeling more connected to the artist than ever before.
Soft ground etching
There are two main points of difference between normal and soft ground etching. The first lies in the etching ground itself. Unlike normal ground, which is quite hard, soft ground is exactly that – soft. It is made by adding grease or tallow (a rendered form of beef or mutton fat) to the normal ground which, as with etching, is then spread evenly over the metal plate. The second difference lies in the application of a sheet of thin paper over the plate’s surface, before any etching is commenced. The illustration is then drawn onto the paper with a pencil. Where the pencil strokes have been made, the paper will adhere to the ground, and when that paper is gently pulled up, the ground is lifted away with it. The plate is then subjected to acid, as in normal etching, which bites into the exposed metal, creating incised lines which will later appear in the print. The result is quite different from a normal etching and entirely different from an engraving. Depending on both the type of pencil and paper used, the print could be quite fine or it may appear rather course – either way, it will not reflect precision in the way an engraving does, resembling instead something much more like a freehand pencil drawing. Where a fine point pencil is combined with a fine grained paper, the printed lines will appear clear and reasonably sharp; where a softer pencil is combined with a course paper, those lines will be less clear. Similarly, varying the pressure of the pencil can impact on the amount of ground that attaches to the paper, creating lines of varying thickness and tone on the final print. It’s actually possible that the ground will not adhere to the paper, even where it has been drawn upon, leaving the print with a broken, almost dotted effect, where there should have been a line. Perhaps some of the most exquisite etchings, however, are those which have the appearance of an all-over textured background, the etcher having first experimented with burnishing or impressing textured paper or cloth over the entire plate surface. These differences between normal and soft ground etching are quite subtle but, when combined, they give the latter its trademark freehand sketch appeal.
Before any etching could take place, the copper plate was first cleaned and polished and fastened into a vice. This was then held over heat until the plate was too hot to touch, and the etching ground (wrapped up in a piece of silk) was spread evenly over its surface, melting through the cloth and ‘laying a ground’, as it was known. When the ground began to cool and harden it was blackened with lampblack. Traditionally, this was done by turning the plate ground-side down and moving a flame, usually from a candle, underneath it, backwards and forwards, until the entire ground turned a shining black. This allowed the etcher to see the progress of their work.
Transferring the illustration to the plate could be achieved in a number of ways. It was rare for an etcher to draw directly onto the ground, just as it was rare for the original artwork to be the same size as the intended final print. Where an original illustration had to be reduced in size, the etcher cleverly used compasses and rulers to measure and divide the image into equal parts, usually squares, such that it resembled a grid. They then took a sheet of smooth writing or tracing paper the size of the intended etching, taking into account the necessary half-inch marginalia, and drew upon it the exact same number of squares. With a pencil, they would then copy the contents of each square into the smaller, corresponding square on the tracing paper. This paper, slightly dampened, was placed face down on the etching ground and the whole passed through a rolling press, essentially transferring the illustration, in reverse, onto the ground, and providing the etcher with the lines needed for scraping. Occasionally, the original illustration was to be the same size as the final print, so the etcher could place transparent paper over it and trace the outline with a lead pencil and transfer it to the ground, as in the above process.
The image transferred to the ground, the etcher then began to scrape through that ground, along the pencil lines, using needles of varying thickness, and creating darkness in the final print with close lines and depth with crossed lines. The object was not to cut into the metal plate but to scratch into the ground to expose its surface; the acid would do the rest. Where a mistake was made in the etching, a small brush with soft natural hair bristles, tapering to a point, could be used to carefully apply Brunswick black, a quick drying varnish, to the plate and, when dry, the lines etched again.
With the scraping complete, the etcher prepared for the acid process, creating a border or wall of wax around the edges of the plate (leaving a spout at one corner) to form a tank to hold the acid and eventually pour it off. The acid, usually a mixture of nitrous acid, water and sal ammoniac (a potash mineral), was then gently poured onto the plate and left to “bite in” to the metal where the etcher had scrapped away the ground. Exactly how long the plate should be left in the acid was crucial, and not without complication. The finest of etched lines required only minutes of submersion; the blackest could require hours. As Roger Baynton-Williams pointed out in The art of the printmaker 1500-1860, acid also worked at different speeds according to how much it had been diluted and the temperature of the surrounding environment; some even bit downwards as well as sideways which put closely etched lines at risk of running into each other. Add to all this, the fact that it was not possible to judge the progress of the ‘bite’ when the plate was submerged in acid. For these reasons, etchers tended to take a repeat approach to the method, leaving the plate in acid for just a few moments initially, then pulling it out, cleaning it, wiping it dry and ‘stopping out’ the finest parts of the print. This process of stopping out involved reapplying ground or Brunswick black to the lines that were deemed sufficiently bitten in, essentially covering them up and protecting them from further erosion when the plate was submerged for a second time in the acid. To achieve the next degree of depth in the illustration’s lines, the plate was left longer in the acid, before being removed and inspected again. In The art of engraving… Fielding suggested that “three bites are generally sufficient for most painters’ etching”.
The image now etched, the wax wall was removed from the plate by warming its edges on the underside. The entire copper plate was then cleaned, usually with turpentine, rubbed with oil, washed again with spirits, dried and taken to the printers. Here, a proof was made by first inking the plate, pushing the dye into the acid bitten lines with a cloth and then wiping away any excess from its surface. A dampened piece of paper was then placed on the clean copper plate and the whole run through the press. If the etcher felt that this proof still required more work, another layer of ground had to be applied to the plate’s surface - a transparent ground that would allow them to see through to the original etching below. They could then open up the lines again, re-etching more detail or depth.
 Bland, David, A history of book illustration: The illuminated manuscript and the printed book, London, Faber and Faber, 1969, p. 153.
 Some excellent traditional and modern recipes for etching-ground can be found in Anthony Gross’ Etching, engraving, & intaglio printing, London, Oxford University Press, 1970, pp. 68-73
 Baynton-Williams, Roger, The art of the printmaker 1500-1860, London, A & C Black, 2009, p. 84
 Fielding, T. H., The art of engraving, with the various modes of operation, under the following different divisions: etching, soft-ground etching, line engraving…, London, Ackerman & Co, 1841, p. 23