in 1876, frost joined the art department at the publisher harper & brothers, where he worked with such well-known illustrators as howard pyle, e. w. kemble, frederic remington and c. s. reinhart. while there, he learned a wide variety of techniques, from cartooning to what later came to be called photorealistic painting. frost's color blindness may have helped his excellent use of grayscale. in 1877 and 1878, frost went to london to study with some of the great cartoonists of the time. later, he returned to philadelphia and studied under painters thomas eakins and william merritt chase at the pennsylvania academy of the fine arts.