Some interesting developments within Surrealist painting are: 1- Frottage (rubbing), developed by Ernst and described by him in Beyond Painting, (1948).
2- Grattage (scraping), also a discovery of Ernst, which transferred frottage to to oil painting. In decalcomania (transferring) the image was obtained by laying arbitrary patches of color on a piece of paper. A clean piece was then rubbed gently on top. When separated, strange grottos, exotic vegetation and underwater scenes suggested themselves to the imagination. A picture was made by chance.
3- Fumage (smoking) was a technique of automatism invented by Wolfgang Paalen (1907-1959) in the late 1930s. Here the chance imagery was provoked. by moving a candle under a sheet of paper; and random areas of soot would develop from which the mind could form images. All these techniques depend for their application upon the hallucinatory mind of the artist.