Emil Ranzenhofer's graphic art works include poster design, book illustrations, watercolors, oil paintings, and etchings, including ExLibris (bookplates). By the end of the year 1900, he had established himself as an innovator in the art of poster design and had a robust commercial career. He illustrated some twenty-seven books in the Kushners Bucherschatz series of novels.
Between 1900 and the start of WWI, his career flourished. Many examples of his posters, etchings, ExLibris, oil paintings, water colors, postcards, and illustrated books are dated from this period. Unfortunately, this was before the custom of numbering the etchings as they were printed, so it is uncertain how many were actually produced and sold. According to Fuchs in his Österreichischer Maler des 19. Jahrhunderdts, Emil Ranzenhofer was awarded a Silver Medal in 1914.
He was a member of the Österreichische Küstlerbund and the Alrbrecht Durer-Bund.