Mineral painting or Keim's process, also known as stereochromy, is a mural or fresco painting technique that uses a water glass-based paint to maximize the lifetime of the finished work.
The name "stereochromy" was first used in about 1825 by Johann Nepomuk von Fuchs and Schlotthaurer.[1] In the original technique, pigments were applied to plaster or stone and sealed with water glass to preserve and enhance the colors.[2][3] The method was then improved in the 1880s by Adolf Wilhelm Keim and renamed mineral painting[4][5] or Keim's process.