The article “Una escultura difícil de percibir”, by the artist and critic Leonel Estrada (1921–2012), was written about the exhibition of sculpture by John Castles (b. 1946) at the Galería de la Oficina in Medellín (November 1977). This text is interesting for its identification of three phases in the work done by the Colombian sculptor, who was still young at the time. The writer’s analysis allows us to differentiate several periods in the sculptural process, which Castles inherited, in principle: that is, the rational, constructivist spirit of the sculptor Édgar Negret (1920–2012). For those first sculptures, Castles used aluminum sheets bolted together, as Negret had done; later, Castles made his pieces with welded iron, and around 1979, he turned to cast iron. As a constructive criticism, Estrada states he that he finds these sculptures asphyxiated, seemingly reduced to models in the space at the Galería. That is why he suggests that they should be seen “on a grander scale,” in a natural environment where they could attain a gigantic dimension and would be integrated with the physical environment.
This article, a newspaper clipping kept by Castles in his private files, refers to the sculptor’s third individual exhibition after five years of participating in group shows and national art events. The Galería de la Oficina was established around 1973 by the critic, gallery owner and art curator, Alberto Sierra. At the time, gallery owners such as Eduardo Serrano Rueda (b. 1939) and Alonso Garcés, in Bogotá; Miguel González (b. 1950) in Cali; and Sierra in Medellín worked cooperatively, making it possible to circulate contemporary art exhibitions among these three cities.
John Castles studied architecture, first at the Pontificia Universidad Javeriana in Bogotá (1966−69) and then at the Medellín campus of the Universidad Nacional de Colombia (1969−72). He has been exhibiting his work regularly since 1975. Castles has also served as a professor at the Universidad de los Andes, Universidad Jorge Tadeo Lozano, and most recently at the Academia Superior de Artes de Bogotá (ASAB).
Leonel Estrada was recognized as the organizer and director of the four international art biennials in Medellín sponsored by the Coltejer company, which was a very important local art event for outstanding artists in the 1970s. His initial profession was dentistry, with subsequent studies in the arts, and he was also a member of the International Association of Art Critics (AICA). He was one of the main promoters behind the founding of the Museo de Arte Moderno de Medellín in 1978.