PH 4½-3½ table lamp from Louis Poulsen is excellently suited as a reading lamp on, for example, a desk or bedside table. The shades are made of reflective mouth-blown opal glass in three layers which direct most of the light downwards. They are glossy on the outside and have a matte sandblasted inside that gives off a soft and diffuse light. The iconic three-shade system was designed by Danish Poul Henningsen who, in collaboration with Louis Poulsen, designed the first PH lamps in 1925-1926 for an exhibition in Paris. Here he has used a scientific perspective since the lamp is built based on the logarithmic spiral, a mathematical spiral curve that occurs in many places in nature. This provides an even distribution across the entire curve of the shade and together with the diffuse reflection through the glass, a harmonious and glare-free light is created. The numbers of the PH lamps refer to the sizes of the shades and the letters are from the designer's initials. Feel free to explore the extensive range of PH lamps.