sentences:  Concurrently with his animation work, Alvarado also worked as a prolific comic book illustrator.As noted above, he worked from 1939 to 1941 providing artwork for Funnies Inc. Alvarado returned to the comic book world in 1947, in collaboration with Charles McKimson (brother of animator Robert McKimson).McKimson was the art director at Western Publishing Company, and the two (in collaboration with Charles' brother Thomas) drew the "Roy Rogers" strip under the pen name "Al McKimson."