"Bull Profile Series" by Roy Lichtenstein, 1973
In these prints, Lichtenstein studies the progress of an image from figurative representation to abstraction. The initially recognisable form of the bull in the first panel is, by the sixth, transformed into a geometric abstraction. Gradually, the animal is reduced to its structure - backbone, horns, tail and foreleg - until the only remaining trace is a curved line suggesting horns in the upper-right corner. The relationship between figuration and abstraction is one of the basic issues of twentieth-century art.