Lee Seung Jio (1941–1990) was a pioneering figure in postwar Korean geometric abstraction and a founding member of the avant-garde groups Origin (1962–) and AG (1969–1975). Amid Korea’s rapid modernization, Lee developed a distinctive visual language through his iconic “pipe” paintings, where cylindrical forms dissolve the boundary between two-dimensional plane and three-dimensional space. Executed with flat brushes, masking tape, and sandpaper, his precise, rational compositions stood apart from the gestural energy of Korean Art Informel and the later material focus of Dansaekhwa, establishing him as a singular voice who translated industrial aesthetics into a rigorous painterly vocabulary.

In the late 1960s, Lee began developing his Nucleus series, which became the foundation of his practice for more than two decades. Drawing inspiration from the technological spirit of the space age as well as his own phenomenological experiences—such as fleeting impressions of landscapes glimpsed from a moving train—Lee sought to articulate the mechanics of perception through repeated tubular motifs. While these forms resonate with the illusionistic clarity of Op Art, they also reflect his deeper engagement with phenomenology and structural abstraction. His sustained dedication to the nucleus as both a visual and conceptual device earned him critical recognition, including multiple prizes at the National Art Exhibition between 1968 and 1971.

Nucleus 74-9 (1968–1974) marks the full articulation of Lee’s signature pipe motif, transforming it from an experimental form into the structural framework of an entire composition. The stacked cylinders, rendered with metallic density through his flat-brush technique and meticulous sanding, create a rhythmic optical field that oscillates between solidity and transparency. Vibrant flashes of red and blue interrupt the structural order, intensifying both spatial tension and chromatic resonance. First developed in the years following Nucleus 10 (1968), this painting exemplifies Lee’s growing confidence in treating the nucleus as a condensed field of perception—one that transcends figuration to probe illusion, rhythm, and structural clarity as the very essence of painting.