In 1907, Demorest decided to pursue a career in art. He studied drawing for several months, in South America. After returning to America, Demorest spent six months studying at the School of the Museum of Fine Arts in Boston and illustrated The Bishop's Men, published by Herbert L. Turner. Demorest then went to New York to study at th e Art Students League where he worked under Frank Vincent Du Mond. While in New YorkDemorest illustrated a book published by D. Appleton and Company.
Having heard Howard Pyle Lecture at the Art Students League, Demorest came to Wilmington in the spring of 1908. For a while Demorest had a studio at 804 Orange Street. Then he used the top floor of his parents home on South Clayton Street for a studio, which he shared for a short time with W.H.D. Koerner, another Pyle pupil he had known at the Art Students League. While in Wilmington, Demorest worked for various children's magazines in Philadelphia and also illustrated several books For the Reed Publishing Company of Boston. In addition to drawing several covers, for the Christian Herald Magazine he also worked for Gunthers, Smith's, and Boy's Magazine.