He worked under George de Forest Brush, who was known for his romantic scenes of American Indian life.

He developed his own unique style of simplified figures with bold outlines in settings free of extraneous detail.

[4] Penfield lived in New Rochelle, New York, a popular art colony among actors, writers and artists of the period.

As artists like Alphonse Mucha, Théophile Steinlen and Toulouse-Lautrec popularized the poster in Europe, Penfield accomplished the same feat in the United States.

For his posters, Penfield utilized simple shapes and a limited palette of colors that lent themselves to the primitive methods of reproduction of the era.