When selecting the stone, it is important to check whether it is completely flat. The preparation starts with removing previous grease images with coarse carborundum (metal powder). The stone is then further grained with finer carborundum and made receptive to grease with vinegar. The stone is drawn or painted upon with a greasy material. Lithographic crayons or -pencils can be used for drawing and tusche for painting. The stone is then twice prepared with etching gum: A mixture of arabic gum and nitric acid. The 1st preparation is to secure the drawing in the stone. During the 2nd preparation you replace the drawn image with the image in penink (roll-up ink). The eventual image is now clear and any unwanted parts can be removed. Then the stone is treated with etching gum again and the preparations are completed.
When printing the pen ink is replaced with a printing ink. This procedure corresponds to the 2nd preparation minus the treatment with etching gum. The stone is damp during printing. It is slowly rolled in with printing ink. After removing the pen ink, a “grease image” is left. Here the water drains and the oily ink adheres to the image. Then you print. The image must be built up slowly to avoid losing the nuances of the stone. You do this by test printing on different types of paper. When satisfied with the result, you start printing your print run.
Materials such as litho stones in various sizes, lithographic crayon, tusche, carborundum, Arabic gum, acid and various inks and papers are available in our workshop. With large format, lithographic crayon and tusche are used in consultation.
Prior to your project, discuss the timeline with one of our advisors.