blot drawing, technique in the visual arts of using accidental blots or other aleatory stains on paper as the basis for a drawing. Leonardo da Vinci was one of the first to expound the value of such accidental marks (in his case he referred specifically to marks on walls) as a means of stimulating the artist’s imagination and providing him with the foundation of a composition.
In 1786 the English drawing master Alexander Cozens published an instructional manual, A New Method for Assisting the Invention in Drawing Original Compositions of Landscape, entirely based on the development of blot drawing. In more recent times, the technique has been exploited by the Surrealists, as in the drawings of Max Ernst and, later, by Bruce Connor.