Lygia Pimentel Lins, better known as Lygia Clark, was a Brazilian artist best known for her painting and installation work. She was often associated with the Brazilian Constructivist movements of the mid-20th century and the Tropicalia movement. Along with Brazilian artists Amilcar de Castro, Franz Weissmann, Lygia Pape and poet Ferreira Gullar, Clark co-founded the Neo-Concrete movement. From 1960 on, Clark discovered ways for viewers to interact with her art works. Clark's work dealt with the relationship between inside and outside, and, ultimately, between self and world.