I. Materials and techniques
Source: Oxford University Press
Artists in the 19th century customarily employed a drawing medium of carbon pigment, binders and fatty substances, including soap, applied to a slab of porous limestone. Although artists have utilized the most recent discoveries, many still value stone for its fidelity to every nuance of the hand. To make a lithograph on stone, the surface is ground with abrasives to prepare a grease-free surface, which can be smooth or coarse, to suit the intended image. The drawing medium comes in solid sticks of various consistencies or as tusche (Ger.: ‘ink’), which is diluted with distilled water or more volatile solvents for application by pen or brush. When the drawn stone has been treated with a mixture of acid and gum arabic (called ‘the etch’ but not related to intaglio printing), adsorption bonds the greasy constituents to the stone, creating insoluble particles so integral to its surface that it can be reused only when they have been ground away. The ‘etch’ also creates a water-loving barrier to resist grease, thus establishing image and non-image area simultaneously. After a solvent has removed the pigment in the image to leave only the grease, impressions are made by sponging the stone with water, then inking the image with a roller bearing oil-based printing ink. Drawn areas repel water and attract ink, undrawn areas retain water and repel ink. Lithographs from zinc—sometimes called zincographs—are made in a similar way.
To draw a pen lithograph the stone must be polished, whereas for crayon work the stone is roughened. A granular effect imparted by the ‘tooth’ of a stone or plate is therefore natural to chalk or crayon and can be mistaken for the intaglio ‘crayon manner’. In the 19th century burin engraving was imitated by needling the image through a water-soluble ground to admit grease selectively to the stone. A mezzotint manner (Fr. manière noire), perfected in the 1830s, entailed modifying a coating of drawing medium with tools or abrasives. From c. 1840 lithotint simulated watercolour with diluted tusche—a procedure so tricky that wash (Fr. lavis) was often imitated by rubbing crayon. For Senefelder’s sprinkled manner (Fr. crachis), a shower of liquid medium was spattered by passing a knife across a loaded brush and controlling the random half-tone by stencil or gum stop-out; airbrushing is a later variant. Artists have also harnessed the effects of oxidation on zinc, known as peau-de-crapaud (Fr.: ‘toadskin’).
Senefelder devised a way of writing with a special liquid on prepared paper and transferring it to stone by damping it and passing it, face down, through the press. Chalk drawings too can be transferred, as can inked impressions from relief blocks, intaglio plates or ‘mother stones’ replicated for the speedier delivery of large editions. Whereas a direct drawing reverses when printed and must be conceived back-to-front, transferred images are returned to their original orientation by double reversal. Senefelder believed this ‘the principal and most important part’ of his discovery.
Lithographs can be crudely printed by placing paper over an inked image and rubbing it from the back, but Senefelder built an upright pole press with a hardwood scraper-bar pulled under pressure across a greased tympan holding the sheet of paper against the inked stone. Professor Hermann Joseph Mitterer (1764–1821) of Munich designed the ‘star wheel’ or cylinder press c. 1805, keeping the scraper-bar stationary and moving the stone; this was forerunner to the French Brisset press, which dominated the Continent by the mid-19th century. In the late 20th century similar presses were still used by some printers and artists continuing the craft of hand-printing.
A separate stone or plate is normally used to print each colour, but small rollers can localize many colours on one surface, and skilful printers can seamlessly blend a number of inks on the roller—a technique called ‘rainbow roll’ or iris printing. The grey scale in monochrome lithography is unparalleled. Traditional lithographs look soft and flat, with veils of ink rather than palpable deposits. While thousands of impressions can be taken from robust crayon work, delicate washes wear more rapidly. No clue as obvious as an intaglio platemark betrays the process, but as the scraper-bar smooths the paper it may leave a trace of the stone’s rounded corners or the metal plate’s sharper perimeter.
After 1850 commercial and ‘artistic’ or fine art lithography began to diverge as a result of mechanical and photochemical developments. Senefelder foresaw automated damping and inking, but the Sigl press, patented in Austria and France in 1851, was the first successful powered machine. It produced up to 1000 sheets an hour—some ten times faster than manual presses. Such speeds could only be attained by using highly polished stones. As the flood of commercial colour printing increased during the second half of the 19th century, armies of chromolithographers, so skilful that they were able to make colour separations by eye, had to render tonal values by pen stippling. In 1879, Benjamin Day (1836–1916) marketed labour-saving ‘shading mediums’ to facilitate the task, and by 1887 chromolithographic draughtsmen could choose from many different patterns embossed on to flexible sheets to be inked and transferred to the stones. As a result of this increasing mechanization, the word ‘chromolithograph’—which simply means a lithograph in colour—became a pejorative term, particularly as it was usually applied to reproductive rather than to ‘original’ printmaking.
The first photolithographs were made in France, c. 1852, by the printer Rosé-Joseph Lemercier (1803–87), helped by an optician and two chemists. Stones coated with light-sensitive asphaltum were exposed under paper negatives for a set of architectural subjects called Lithophotographie; ou, Impressions obtenues sur pierre à l’aide de la photographie (Paris, 1853). In 1855 Alphonse-Louis Poitevin patented an alternative, using chromates on a mixture of albumen and gelatin. Lemercier bought the rights in 1857, but both methods proved commercially uneconomic. Line photolithographs were developed for cartography in 1859 by Eduard Asser in the Netherlands and J. W. Osborne (1828–1902) in Australia. Osborne transferred images on photosensitized paper to stone. Col. Henry James (1803–77), Director of Ordnance Survey in England, adapted the method to zinc in 1860. Despite many experiments, such as a patent of November 1865 to copy photos on to sensitized transfer paper impressed with an aquatint grain, photolithography lacked commercially viable half-tones. ‘Ink photos’ from reticulated gelatine provided tonal transfers in the mid-1880s, but half-tone screens were satisfactorily combined with the process only in the early 20th century.
Offset lithography—an extension of the principle of double reversal previously achieved by transfer paper—was first used on tin in 1875. The inked image was transferred to rubberized cloth, thence to metal. By 1904 Ira Rubel of New Jersey had built the first practical offset press for paper. One cylinder carried a curved metal printing plate automatically inked and dampened, the second a rubberized ‘blanket’ to relay the image, the third a sheet of paper to be printed. By 1910 speeds reached 5000–6000 sheets an hour. When photomechanical and photochemical techniques were combined with web-fed paper, simultaneously printed on both sides, offset outstripped most other mass-production methods.
Transparent plastic plates, used for mapmaking during World War II, were developed for artists after 1945, notably by W. S. Cowell. Photocomposition and electronic scanners able to convert transparencies into trichromatic half-tones appeared in the 1950s. Screenless or continuous tone lithography became viable c. 1960, when hand-drawn or photo positives on translucent film could be transferred by ultra-violet light to sensitized polymer-coated anodized aluminium plates.
Despite the fact that offset plates can also be hand-drawn, the technique’s association with photomechanical production and supposed lack of ‘originality’ rendered it suspect for ‘art’, especially in the USA c. 1960. By the early 1970s this prejudice had been largely overcome and offset proofing presses increasingly adopted by artists’ printers. Offset impressions are lighter than those from a direct press; the image suffers less wear, and many colours can be superimposed with precision. These characteristics make it an attractive process for the painter.
From Grove Art Online