He was one of the most visible artists in the local avantgarde art of the post-war years. His style evolved from lineal abstraction influenced by surrealism (during his Dau al Set years) towards Art Informel working with texture, color and graphism. His work also includes a variety of posters, books, murals, stained glass, mosaics, jewelry and opera scenography. També va fer cartells, il·lustrà llibres i va fer murals, vitralls, mosaics, joies i fins i tot escenografies d'òpera (Spleen de 1984).
In 2000, Tharrats himself collaborated with monumental and small oil paintings in his last exhibition which was organized by Galeria Taüll of Barcelona.
In 2009, an important traveling exhibition called "Les maculatures de Tharrats" was arranged by the Cultural Department of the Diputació de Barcelona. [2]
^«L'Àrea de cultura de la Diputació de Barcelona ofereix als municipis dues noves exposicions de Arranz Bravo i Joan Josep Tharrets». Bonart [Girona], núm. 114 (abril 2009), p.25. ISSN 1885-4389.