Poul Henningsen designed the three-shade system in 1925-1926, partnering with Louis Poulsen for a Paris exhibition. The PH 2/1 Wall Lamp is part of a thirty-light three-shade family, including three for outdoor use. PH's system includes 1000 models, in various sizes, colors and materials, from table, floor and wall lamps to chandeliers. The logarithmic spiral enabled even light distribution and control of glare/shadow. The model numbers refer to the shade size, with the PH 2/1 a ‘hybrid’ size consisting of an approx. 20 cm top shade and lower shades from the 1/1 model. The ‘whole’ size models, like the 2/2, feature top shades of 20 cm corresponding to the 3:2:1 middle/lower shade proportions. PH’s ‘whole’ size fixtures are designed to be particularly glare-free and hang