In 1967, Mathey succeeded in bringing Jean Dubuffet's personal collection into an "institution", the museum of decorative arts, even though the artist rejected academic structures. Mathey was interested in the artist Jean-Joseph Sanfourche, who was selected for important exhibitions "Des singuliers de l'art" in 1978 at the Museum of Modern Art of the City of Paris and at the Museum of Decorative Arts, in 1980, as part of the "international heritage year".