Regardless of having completed a university degree in chemistry, Willys de Castro worked as a painter, printmaker, theatre designer, graphic designer, concrete poet and composer. In 1953 he began producing his first works in a constructivist orientation. It was also during the mid-1950s that he began producing visual poetry, of which Cartaz-poema-Bridge is one of the key examples that exists. Around this time, fellow artist Hercules Barsotti opened a graphic design studio, and these activities would have brought de Castro within the realm of the Sao Paulo concrete art (and poetry) groups.

In 1958 he went on an educational trip to Europe. The following year, on his return, de Castro became a founding signatory of the 1959 Neoconcrete Manifesto in Rio de Janeiro with fellow artists Hercules Barsotti, Ferreira Cullar, Franz Weissmann and Lygia Clark. The group formed as a reaction to the perceived orthodoxy of Sao Paulo concrete art and poetry. His involvement in the movement would substantially further its theoretical engagement with phenomenology, being both highly significant and original. The artist made Cartaz-poema-Bridge at this exact moment of declaration and crystallization of his ideas.

Following this seminal moment (from 1959 onwards) de Castro developed the notion of the Active Object [Objeto Ativo], which questioned the two-dimensional nature of the traditional canvas as the only possible support for painting. Composed of rectangular pieces of painted wood like wooden reliefs, they were painted in an abstract geometric manner. These objects are fixed on the wall, creating a situation that is both a painting and a sculpture.

The admiration for Willys de Castro's oeuvre cannot be overstated, and this work marks a crossroads in a career that has been highly influential not only in Brazil but on an international scale.