Plein air

Plein air (from the French for «open air») is the practice of painting finished pictures outdoors rather than in the studio, in order to observe natural light, colour, and atmosphere directly. Although artists had long made studies from nature, the custom of executing the final work itself outdoors spread in the nineteenth century. This was aided by technical innovations, above all the invention of oil paints in metal tubes (around 1841), which made materials portable. Important precursors of plein-air painting were the masters of the Barbizon school, notably Camille Corot and Théodore Rousseau, who worked in the Forest of Fontainebleau. The principle of plein air was most fully embodied by the French Impressionists — Claude Monet, Auguste Renoir, Camille Pissarro — for whom the rendering of momentary effects of light and time of day became the chief aim. Monet painted series of the same motif under different lighting, so as to capture the changeability of the atmosphere. Plein-air painting transformed the very conception of colour and light and deeply influenced the subsequent development of European art.