But, that late Enlightenment period sees dynamic changes in printed form and content alike. Aiming to capture the dramatic contrasts of light and dark achieved in the famous "candle-lights" of his friend Joseph Wright of Derby, Liverpool experimental Peter Perez Burdett, for example, developed (well, he said he invented it, but ...) a method of aquatint printing. In Burdett's process, rosen would be distributed across a copper plate, then heated to form tiny chemical indentation in the plate capable of bearing ink, which would then be pressed onto the dampened paper to read as the dark, velvety textures necessary for rendering Wright's works. "Impressions chemically wrought" as Burdett's prints were described at exhibition in the early 1770s.
For the scale, speed and ease of production requisite to addressing modern mass audience, few period methods could rival the new technique of lithography. And, so that we could all learn more about liquidy processes of subtending that technique, our class made a visit to the well-equipped studio facilities at a nearby university. There, two graduate students (Hideki, who stands in profile on the left above, and Aanchal who appears in the photos below) gave us some practical demonstrations.
The crucial principle of lithography is the chemical resist between oil and water. Invented by musical-printing entrepreneur Aloys Senefelder in the mid-1790s, so Hideki told us, the traditional lithographic process requires a finely smoothed limestone surface, which can be treated for printing, then ground down and re-used. As you can probably guess from the examples on metal work table at left, these blocks are extremely heavy! Once the limestone surface has been made flush, the image-maker draws or paints onto the stone with oily media. As you can see from the example here, our class collaborated on this masterpiece using waxy crayons and a range of other mark-making instruments.
Here, Hideki and Aanchal are working together to keep the chemical action on the stone in order. First, Aanchal wets the stone with water. Then, Hideki rolls on the ink.
Next, a sheet of paper is affixed to the stone and rolled through the press. I think you can understand why everyone would want to get involved in the fun!