Tàpies is responsible, together with the Italian Alberto Burri and the Frenchman Jean Dubuffet, for the creation of a new artistic path, in which the plastic values are based as much on the visual as on the tactile qualities of the materials used. He creates real walls in his paintings, which sometimes appear to us as very structured and serene compositions, and at other times much more free and violent. In this debate he also produced absolutely abstract works without any known visual reference, and in others he introduced calligraphic signs or numbers. The works of this period from 1955 to 1967 are faithful witnesses to the establishment of this novel and personal language based on absolute freedom.