Plein air painting - American Ingenuity: William Preston Phelps was a Boston artist. He studied, alongside other great American artists (William Merritt Chase, Frank Duveneck, James McNeill Whistler, et.), plein air painting in Munich Germany at the Royal Academy. Unlike other plein air artists, however, Phelps did not use the standard umbrella and French-style outdoor easels when he returned to America. Upon his return to America, Phelps painted outdoors all year round and built a horse-drawn mobile shelter that he used for protection from the elements when he painted. Phelps was fascinated by the infinite tints of white, brown, and blue that he perceived in the winter landscape, believing that they required a keener eye for color than do the tints of spring or summer.