Plein-Air Painting

En plein air (French pronunciation: ​[ɑ̃ plɛn ɛːʁ], French for outdoors, or plein air painting) is the act of painting outdoors. This method contrasts with studio painting or academic rules that might create a predetermined look.

Artists have long painted outdoors, but in the mid-19th century, working in natural light became particularly important to the Barbizon school, Hudson River School, and Impressionists.

In 1830, the Barbizon School in France, founded by John Constable, enabled artists like Charles-François Daubigny and Théodore Rousseau to more accurately depict the appearance of outdoor settings in various light and weather conditions. In the late 1800s, the en plein air approach was incorporated with the impressionists’ style, and artists such as Claude Monet, Pierre-Auguste Renoir, and Edgar Degas began creating their work outdoors. From France, the movement expanded to America, starting in California then moving to other American locales notable for their natural light qualities, including the Hudson River Valley in New York.

The Newlyn School in England is considered another major proponent of the technique in the latter 19th century. The popularity of painting en plein air increased in the 1840s with the introduction of paints in tubes (like those for toothpaste). Previously, painters made their own paints by grinding and mixing dry pigment powders with linseed oil.

The act of outdoor painting from observation has been continually popular well into the 21st century.

It was during the mid-19th century that the box easel, typically known as the French box easel or field easel, was invented. It is uncertain who developed it, but these highly portable easels with telescopic legs and built-in paint box and palette made it easier to go into the forest and up the hillsides. Still made today, they remain a popular choice (even for home use) since they fold up to the size of a brief case and thus are easy to store.

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Wikipedia