Nigro made works on wooden structures on which he applied tempera paint, which meant that, on the one hand, he did not abandon paint as a medium and, on the other, he managed to overcome the deadlock created by the two-dimensional canvas. 

The works of this period point in a direction similar to that adopted, with the use of shaped canvas, also by some American artists, such as Frank Stella, Ellsworth Kelly, Robert Mangold, and Richard Tuttle, and Richard Smith in England.

There were basically two different types: the so-called “modular and environmental structures”, also known as “modular”, such as Dallo spazio totale, 1954-64, Dallo spazio totale 1954: 4 colonne prismatiche a progressioni ritmiche simultanee (passaggio psicologico), 1966, and Dallo spazio totale: progressioni ritmiche simultanee opposte, 1965, as well as the “trellises” that can be seen in the next gallery.

Elementary forms and primary colours, lines and interweaving outlines all appear in the search for total space and total time. In various visual variations and modulations, they anticipate the reflections on trace and colour that were to feature in later radical and Minimal trends. 

Dallo spazio totale 1954: 4 colonne prismatiche a progressioni ritmiche simultanee (passaggio psicologico), 1966, is a work that consists of four wooden elements each 284 cm high, which stand out like totem poles in the space. It has been set up here respecting the positioning that the artist himself wanted and implemented at the 34th International Art Exhibition of the Venice Biennale in 1968.

In Dallo spazio totale: progressioni ritmiche simultanee opposte, 1965, the artist tests our perceptive capacities to the extreme. By distributing the lines that form the grid on each of the two wooden panels, making it very dense on one side and sparse on the other, the panels appear to be slightly trapezoidal. In actual fact, each element is really a true rectangle.