Which artist used fluorescent light tubes as his primary medium?

Dan Flavin used fluorescent light tubes as his primary artistic medium.

Flavin transformed commercially available fluorescent lamps and their fixtures into minimalist sculptures and installations. Rather than treating light merely as illumination, he used it to alter walls, corners, floors, and entire rooms. The colored glow extends beyond the physical tubes, making the surrounding architecture part of the work.

Flavin began sketching ideas for electric-light art in 1961 and started working seriously with fluorescent tubes in 1963. He used standard lengths—commonly two, four, six, and eight feet—and commercially produced colors including red, yellow, blue, green, pink, ultraviolet, and several whites. The ordinary hardware-store origin of the materials was important to his rejection of traditional sculptural materials.

Flavin’s works are sometimes confused with neon art or with James Turrell’s immersive light environments. Flavin’s characteristic medium was fluorescent light, arranged in repeated, often geometric configurations. His celebrated series “monument” for V. Tatlin pays tribute to the Russian Constructivist Vladimir Tatlin while demonstrating how light can define three-dimensional space.