Plein air is French for 'outdoors' or 'outside', open air and is a term applied to painting outside, transfer to a picture of all riches of changes of the color caused by influence of a sunlight and the surrounding atmosphere.

Plein-air painting has developed as a result of work of artists on open air (instead of in workshop), on the basis of direct studying a nature with the purpose probably fuller reproduction of its real shape. Some moments anticipating occurrence of plein-air painting, it is possible to track in creativity of masters of the Italian Revival and artists of 17 century. However in essence principles of Plein air were extended in the first half of 19 century.

Principles of Plein air found the fullest expression in the second half of 19 century. In creativity of masters of impressionism (then term "Plein air" starts to be used widely) - Claude Monet, Camille Pissarro, Pierre-Auguste Renoir, etc. In Russia in the second half of 19 - the beginning of 20 centuries of significant successes in plein-air painting achieve Vasily Polenov, Isaac Levitan, Valentin Serov, K.A. Korovin , I.E. Grabar . Interest to problem of plein air was kept also in painting of 20 century.