A Sunday Afternoon on the Island of La Grande Jatte (Un dimanche après-midi à l'Île de la Grande Jatte) was painted from 1884 to 1886 and is Georges Seurat's most famous work. A leading example of pointillist technique, executed on a large canvas, it is a founding work of the neo-impressionist movement. Seurat's composition includes a number of Parisians at a park on the banks of the River Seine. It is in the collection of the Art Institute of Chicago. Georges Seurat painted A Sunday Afternoon between May 1884 and March 1885, and from October 1885 to May 1886, focusing meticulously on the landscape of the park and concentrating on issues of colour, light, and form. The painting is approximately in size. Seurat completed numerous preliminary drawings and oil sketches before completing his masterpiece. One complete painting, the study featured to the right, measures 27 3/4 x 41 in. (70.5 x 104.1 cm) and is on display in the Metropolitan Museum. Inspired by optical effects and perception inherent in the color theories of Michel Eugène Chevreul, Ogden Rood and others, Seurat adapted this scientific research to his painting. Seurat contrasted miniature dots or small brushstrokes of colors that when unified optically in the human eye were perceived as a single shade or hue. He believed that this form of painting, called Divisionism at the time (a term he preferred) but now known as Pointillism, would make the colors more brilliant and powerful than standard brushstrokes. The use of dots of almost uniform size came in the second year of his work on the painting, 1885–86. To make the experience of the painting even more vivid, he surrounded it with a frame of painted dots, which in turn he enclosed with a pure white, wooden frame, which is how the painting is exhibited today at the Art Institute of Chicago. The Island of la Grande Jatte is located at the very gates of Paris, lying in the Seine between Neuilly and Levallois-Perret, a short distance from where La Défense business district currently stands.