Like many of the poster artists of the time, Grun sold illustrations to magazines to earn a living. Dwelling as he did in the bohemian quarter of Paris, he frequented local cafes and cabarets, and that led him offering his services for interior decor and stage sets. Grun did multicolored decorations and backdrops for La Scala, le Concert Parisien, le Carillon, le Joyeux-Théâtre, and Decadent's Concert (among others).
Happy with the results, the establishments began to commission him to produce posters for the shows they were staging. Grun ''officially'' began his poster designing career in 1892
He gained national notoriety for his work with color posters. Only the most famous Montmartre cabaret singers were shown in his posters. Grun created most of his posters at his Paris studio, located at 31 Boulevard Berthier.
They were printed by Impremerie Chaix, one of the largest printing firms in Paris. Jules Cheret, arguably the most prolific poster artist in history, was Chaix's artistic director. As such, there was a fierce competition between Cheret and Grun for the spotlight.
Jules-Alexandre Grün, was a French painter, illustrator, and poster artist. He was born in Paris, on May 25th, 1868. He died of Parkinson's Disease, although the date of his death is debated. Some sources state that he died on February 15, 1934, while others, such as the Salon de Paris official documents claim 1938. Yet another source claims 1945. Grun was the pupil of Jean-Baptiste Lavastre, the famed theatrical decorator of the Paris Opera, and of Antoine Guillemet, a renowned landscape painter. Still life, portraits, and scenes of Parisian life were his favorite subjects. In 1890, his illustrations for Xanrof's Chansons sans Gene (1890) and Chansons à rire (1891) made him the poet of the Bohemian element and the Montmartre atmosphere.