Between 1959 and 1963 De Castro made a series of sculptures and painted wall reliefs he called Active Objects. The simple, rhythmic color pattern in this work shifts as a viewer circles it, "activating" the space between object and viewer. In 1959 De Castro joined the Brazilian Neo-Concrete art movement, which in its founding manifesto cites Piet Mondrian as a "true artist." Like Mondrian, Neo-Concretists believed in the power of abstract art to communicate universally, transcending specific circumstances. De Castros work was included in the 1960 exhibition Concrete Art: 50 Years of Development, organized in Zurich by Max Bill.
Gallery label from 2010.