Slavko Kopac: Surrealist, Art Brut advocate, and key figure in Informal Art. This volume explores his multifaceted work across various media, highlighting his essential role in defining and promoting these movements. Text in English, French and Italian.Slavko Kopac. Hidden Treasure. Informal Art, Surrealism, Art Brut accompanies the exhibition Slavko Kopac. Hidden Treasure (Accademia delle Arti del Disegno, Florence, September–November 2025). With an introduction by Bernard Blistène, honorary director of the Centre Pompidou and advocate of the acquisition of twelve of Kopac’s works into the museum’s collection, the book explores a multifaceted artist, deeply connected to Surrealism, Informal Art, and Art Brut. A key collaborator of Jean Dubuffet and the first curator of the “Collection de l’Art Brut”, he played a fundamental part in its promotion and configuration. His magical, totemic universe captivated the Surrealists and led to a collaboration with André Breton. At the same time, critic Michel Tapié included him in Un Art Autre (1952), recognizing his originality within the Informal Art movement. He used painting, drawing, ceramics, sculpture, collage, and art books to explore materiality, intertwining reality and fantasy. The volume features contributions by leading international scholars and an extensive iconographic repertoire, including previously unpublished works and archive documents. Text in English, French and Italian.