The Just Normlicht GmbH is the most famous manufacturer of standard lighting solutions in the printing sector. The company Just from the Swabian Weilheim / Teck sells alongside the classic D50 and D65 standard light tubes and various proof lights, stations and light booths, where prints can be checked under standardized lighting. In recent years, the LED technology has been introduced, so that now several devices with LED technology are offered. Another well-known company is GTI; Standard light tubes are also manufactured by OSRAM and other manufacturers.
A standardized light is called a defined light condition under which the viewer can view and assess prints or objects uniformly. The most important standard illuminants D50 are in accordance with ISO 3664:2009 for printmaker and for colour matching in prepress and press (colour temperature: 5,000 kelvin) and D65 (colour temperature: 6500 K) for internet graphic designer. D65 is the default setting for most monitors.
Other important types of light are TL84, the standard neon light (colour temperature: 4,100 kelvin), which dominates factories and supermarkets, and A – incandescent light (light bulb) with a colour temperature of 2,700 Kelvin.