He graduated to the magazine L'Illustration in 1927 through 1934, but continued increasingly to focus on Scout-centered art in Scouting publications.

The style of Joubert's illustrations depicted idealized boys experiencing the glories of Scouting and comradeship.

Joubert is considered, owing to his eye for trend and his mass-market exposure, to have had reflective influence[clarification needed] on boy-culture in France from the 1930s until the close of the 1960s.

"[citation needed] He also did work for some right-wing Catholic journals and, as with any artist, the particulars of his patrons have been imputed to him.

[citation needed] Not long before his death, Joubert produced a large volume of memoirs and reprinted art, Souvenirs en vrac.