By the mid-1880s impressionism had won acceptance after a decade of struggle, and the younger generation found it too spontaneous and unstructured. Georges Seurat approached painting with a method drawn from the colour science of the day: Michel Eugène Chevreul's law of simultaneous contrast and Ogden Rood's work on optical mixture. Colour mixed on the palette turns muddy and dark; pure colours placed separately combine in the eye at a certain distance and keep their brilliance.

Un dimanche après-midi à l'Île de la Grande Jatte is two years of applying that principle: Parisians at rest on a Sunday on an island in the Seine, built from millions of small points of colour. The result, contrary to impressionism, is a frozen and almost ceremonial scene — figures in profile, upright and motionless, the composition set out in a geometry close to the golden section. Seurat also frames the painted surface with dots applied to the edge of the canvas itself.

The painting was shown at the last impressionist exhibition in 1886 and caused argument; the critic Félix Fénéon named the approach 'neo-impressionism'. Seurat died at thirty-one, but the method — pointillism, or divisionism — passed through Signac to Matisse and fauvism, and through Boccioni to futurism. Its longer effect is conceptual: the idea that painting can rest on a theory of how the eye and colour work is one of the preparations for twentieth-century abstraction. The picture is now at the Art Institute of Chicago, which does not permit it to leave the building.