Since his early years in Uruguay up to the end of his career in Spain, drawing was a fundamental form of expression for Pablo Serrano. These drawings are reflections of the concepts which his series were based on. In this collage he attempts to portray the conceptual continuity present across two of his series—Men With Door (Hombres con Puerta) and Joint Unit (Unidad Yunta)—created from 1966. On a page of the catalog from the exhibition which took place in Amberes in 1973 he has drawn one of his 'men,' and on the right an outline for Joint unit. Both demonstrate his deep concern for humanity. In Men With Door he played with the contrast between a deformed body and a polished and brilliant hollow interior accessed through a door, a metaphor for hope in communication, while in Joint Unit he portrays this idea through abstract shapes which, like a puzzle, fit and integrate together into a single piece. He exhibited both pieces in a series of international exhibitions, such as the Guggenheim International Exhibition 1967: Sculpture from Twenty Nations, which toured America, New York.