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 Nucleus series—often referred to as his “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 10 (1968) marks the inception of Lee’s lifelong exploration of the cylindrical motif. First exhibited at the 12th Invited Exhibition of Contemporary Artists at Gyeongbokgung Palace Museum, the work introduces a bold tubular form set against bands of vibrant color, establishing the structural and optical framework that would define the series. To achieve the illusion of metallic density, Lee charged a flat brush with contrasting tones at either end and then meticulously sanded the surface to burnish its reflective depth. This early work encapsulates his synthesis of painterly precision and mechanical aesthetic, signaling both a decisive break from conventional figuration and his commitment to a new visual order grounded in rhythm, clarity, and perception.