PH designed the three-shade system in 1925-1926 and cooperated with Louis Poulsen for an exhibition in Paris until his death in 1967. He aimed to produce glare-free light, direct illumination, and subtle shadows from incandescent bulbs. The PH 2/1 Pendant is one of 30 lights in the three-shade family, including outdoor models. He created over 1,000 models – tables, floors, walls, chandeliers, and more – in various colours and sizes. Shades were metal with painted undersides and later glass was added to the system. PH used the logarithmic spiral for even light distribution and to control glare and shadows. Each shade reduces light equally. Model numbers refer to shade size. The 2/1 Pendant combines an approx. 20 cm top shade with lower shades from the 1/1 model to hang from a lower height.