During the nineteenth century, posters were produced by a process called lithography, literally “stone writing.” Jules Chéret established his own lithographic press, but most other poster artists during Toulouse-Lautrec’s time took their stones to a professional lithographer, who printed the poster in large quantities. Toulouse-Lautrec’s lithograph L’estampe originale shows one such professional in action at his press, while the familiar Jane Avril studies the freshly-printed posters.
To create a poster, the artist first had to obtain a stone; limestone was the preferred choice. The printing surface was ground with abrasive materials to create a perfectly flat face, which, depending on the drawing medium the artist chose, was either roughened or highly polished. The most common medium in the late nineteenth century was a compound carbon-containing pigments, binding substances, and fats (like soap). It was prepared in crayon-like sticks which could be used to draw directly on the stone’s surface, but also came in a form called tusche (from the German for “ink), which was mixed with one of various solvents to form a paint-like substance that the artist could apply to the stone with a brush or pen (Gilmour). Toulouse-Lautrec chose to work this way in order to create more detailed images and cleaner lines, so his keystones had very highly polished surfaces.
Once the drawing medium had been applied, the stone was treated with a compound called “etch,” a liquid containing acid and gum arabic. The etch caused the medium to bind tightly to the stone’s surface; these sites became the areas that later produced the image, because the greasy drawing medium attracted ink. The parts of the stone’s surface untouched by drawing medium formed a hydrophilic coating after being treated with the etch. These areas 
resisted ink by instead attracting water, and formed the blank areas of the poster when printed. After etching, the artist or lithographer sponged the stone’s surface with water, which coated its blank areas. Then, an oil-based ink was applied with rollers; the grease-containing ink was attracted to the drawn surfaces, and cleanly adhered to the image.
Because it was difficult to print multiple colors at once, artists usually created multiple stones for each poster. Different areas would be drawn in with the greasy medium, and then inked with their appropriate color and printed on the same sheet. It was possible, especially in the late 1890s, to print multiple colors cleanly on one stone; Toulouse-Lautrec’s Jane Avril (1899) is an excellent example. One of Toulouse-Lautrec’s favorite ways to apply ink, however, was a technique called crachis, or a sprinkling effect. The artist created this airbrushed effect by running a comb or knife across an ink-loaded toothbrush, thus lightly spattering the stone with tiny droplets of color (Gilmour). The crachis technique is visible in Toulouse-Lautrec’s Au Concert (detail shown at right).
Lithography was a favored medium in the 1890s because of its artistic flexibility. It afforded easily reproducible prints, which made it optimal for poster-making and the production of published illustrations, but its capacity for incredible detail allowed it to maintain a place in the fine-arts sphere. Different types of ink could also be used to distinguish between lithographs; heavy, oil-based inks were used for posters, but prints intended for sale often used a higher-grade, “iris” ink, and were sometimes dusted with powdered metal for added effect (Gilmour).
Lithography is still a viable medium today, though it is no longer used to produce advertisements; poster-making technology continued to improve throughout the twentieth century. However, modern lithography artists carry on many of the practices common in the nineteenth century, and some use the same materials. Printing perfect lithographs is a difficult and detailed enterprise; creating posters like Toulouse-Lautrec’s demands time, precision, skill, and love.
IMAGES
Toulouse-Lautrec, Henri de. L’estampe originale. 1893. Musée Toulouse-Lautrec, Albi.
Toulouse-Lautrec, Henri de. Au Concert. 1896. The Posters of Toulouse-Lautrec. Andre Sauret. Monte-Carlo, France: Andre Sauret, 1966. Plate XXVII.