In 1972 he was invited to the Venice Biennial for graphics. In those years he was busy trying to develop a working "grammar" of his own, mainly using ranges of grays on white backgrounds and almost abandoning color. In 1973, he was invited to the 10th quadrennial in Rome.
Between 1973 and 2004, he taught at the Milan design Polytechnic. His works can be found in collections in the USA, in France, in Germany, in Italy, in the contemporary art collection of New York University, at the Turin Modern Art Gallery, at the modern art museum of Saarbriiken and in many other exhibi tions in the USA, France, Germany and Switzerland.