The term 'post' tells us that this movement followed after the
impressionism (1870-1880). And just as
the impressionism the post-impressionism became a typical French movement.
Already in 1880, six years after the beginning of the Impressionism, a reaction on the movement follows. What had began as a revolution in art, was now accepted. Therefor a large group of artists began experimenting with new methods. This in the believe that the development to a new kind of art had not ended yet. They were all searching for a new and more intense truth behind the painting.
Although they developed themselves in different directions, the main approach was to get trough to the matter in a scientific and more intense way; to find the true nature of the matter.
One of the scientific approaches is called pointillism or divisionism. The artists studied the optic effect of colors. They experimented with this optic effect by creating paintings in which the colors were not blended but in which little points in pure colors were grouped next to eachother. With this method the colors were not blended in reality but were blended in vision. Work like this was theoretical very well grounded. Many drawings were made and it sometimes took the artist about a year to finish his painting. There is no question about impressionistic art anymore, because the artist did not paint the quick impression anymore. They forgot about one of the basic aspects of the impressionistic movement.
Paul Cézanne, the oldest artist of this new generation, made the scientific approach of painting his duty for life. His most famous object of study is the mountain he saw through the window of his studio: the Mont Sainte Victoire. By experimenting with colors and distribution of areas Cézanne tried to control the qualities of these elements.
And it was Cézanne who invented the concept of primary and complementary colors. If one uses these complementary colors in the right combination, the colors will intensify certain effects. For example, red seems more red when we put the color green next to it. To intensify the 'warm colors' by the use of the 'cold colors' is an invention of Cézanne and is still one of the most important principals of painting. Cézanne also divided the scene in different areas. He made the scene more abstract by ungrouping the scene; he made the visible reality abstract. This meant the first step in the direction of the cubism.
Paul Gaugain was inspired by forms and by art from the middle ages. He left all knowledge of realistic painting far behind. In his work is every form of perspective missing and the use of colors is unreal. He also was inspired by plain living people. for example the farmers in France and the Indians of his favorite island Tahiti.
The most famous artist of the post-impressionism is Vincent van Gogh. The development of his painting method is very locally. During his Dutch period van Gogh used dark colors, which was very trendy in Holland at the time. While he visited his brother Theo in Paris, he came into contact with the impressionists. He got inspired by the methods of the impressionists (specially the use of colors) and soon after he decided to move to the south of France, to Arles. By getting into contact with Gaugain, he started experimenting with more vivid colors. Later on, maybe because of his mental state of mind, the stroke of his brush became more aggressive and the layers of paint became thicker.
Because of the style of painting he used during the last period of his life and the energetically expression of his work, van Gogh is called the father of the expressionism genoemd.