what is the medium of a sunday afternoon on the island of la grande jatte
Seurat’s painting was a mirror impression of his own painting, Bathers at Asnières, completed shortly before, in 1884. Whereas the bathers in that earlier painting are doused in light, almost every figure on La Grande Jatte appears to be cast in shadow, either under trees or an umbrella, or from another person. For Parisians, Sunday was the day to escape the heat of the city and head for the shade of the trees and the cool breezes that came off the river. And at first glance, the viewer sees many different people relaxing in a park by the river. On the right, a fashionable couple, the woman with the sunshade and the man in his top hat, are on a stroll. On the left, another woman who is also well dressed extends her fishing pole over the water. There is a small man with the black hat and thin cane looking at the river, and a white dog with a brown head, a woman knitting, a man playing a horn, two soldiers standing at attention as the musician plays, and a woman hunched under an orange umbrella. Seurat also painted a man with a pipe, a woman under a parasol in a boat filled with rowers, and a couple admiring their infant child. 
The border of the painting is, unusually, in inverted color, as if the world around them is also slowly inverting from the way of life they have known. Seen in this context, the boy who bathes on the other side of the river bank at Asnières appears to be calling out to them, as if to say, “We are the future. Come and join us”. 
Seurat’s first major pointillist work was Bathers at Asnieres (1883-4, National Gallery, London). Although rejected by the official Paris Salon, the work was shown at the Salon des Independants, an alternative event co-founded by Seurat himself, where he met fellow pointillists Paul Signac (1863-1935) and Henri-Edmond Cross (1856-1910), who helped him to further develop the idiom. Shortly afterwards Seurat began painting A Sunday Afternoon on the Island of La Grande Jatte, which took him two years to finish. It was exhibited for the first time in May 1886 at the final Impressionist exhibition: an ironic occurrence since the work is now seen as one of the first major examples of Post-Impressionist painting (1880-95).
The painting depicts fashionable Parisians enjoying a Sunday afternoon at a popular beauty spot located on the River Seine between Neuilly and Levallois-Perret. While his earlier Bathers at Asnieres depicted the working class left-bank of the river, this work shows the bourgeois right-bank at La Grande Jatte. Thus, for instance, in contrast to the unremitting heat of Asnieres, La Grande Jatte has plenty of cool shade in which to escape the sun.
Seurat adopted the scientific discoveries regarding how the eye perceives color. Scientists were beginning to understand the difference in the result of mixed material color pigments and mixed colored light, and he believed utilizing these principles could result in a more emotionally evocative work.
Seurat is regarded as the father of the Neo-impressionist art movement, and A Sunday Afternoon on the Island of La Grande Jatte is considered to be the beginning of that movement. Although pointillism was heavily used during this era, it is the theory of light and color, as well as artistic impression of form that truly defines the style.
Georges Seurat, Sunday at La Grand Jatte, 1884, Art Institute of Chicago, detail
It is the most famous example of use of highly systematic and “scientific” technique, subsequently called Pointillism. It relies on the ability of the eye and mind of the viewer to blend the color spots into a fuller range of tones. Seurat himself preferred to call his technique “chromo-luminarism,” a term he felt better stressed its focus on color and light.
The ‘Ile de la Grande Jatte’ translates as ‘Big Bowl Island’ and the immense work by Georges Seurat perfectly depicts it’s character. The island itself is a mile long and located on the Seine in the Neuilly-sur-Seine department of Paris and represented a high class get away for the Parisian community.
A Sunday Afternoon on the Island of La Grande Jatte — 1884 (French: Un dimanche après-midi à ‘Ile de la Grande Jatte’ — 1884) is one of Georges Seurat’s most famous works, and is an example of pointillism.