Brommer is an internationally recognized teacher of watercolor painting and is the author of eighteen art instruction books and numerous articles in art magazines. He served as president of both the California Water Color Society and West Coast Watercolor Society. Through the years he has actively exhibited watercolors, holding 110 one-man shows and having his works displayed in 204 group exhibitions. Since the 1960s, he has been in demand as an instructor of watercolor workshops and has traveled all over the world conducting these classes.