This plein-air oil study by Frederic Church was left unfinished, which gives us a glimpse into his process.

Bavarian Landscape; Frederic Edwin Church (American, 1826–1900)
USA; brush and oil, pencil on academy board.; 27.3 x 30 cm (10 3/4 x 11 13/16 in.)
This area-by-area method of painting is sometimes called "window shading" because it's like pulling down a window shade.
3 Comments on Gurney Journey: Frederic Church's Area-by-Area Process