The control of daylight entering the display rooms of museums and art galleries presents a variety of problems, for not only must the direction and diffusion of the light be controlled, but its destructive action must be limited. Controlling the destructive action of light involves limiting its intensity and removing its ultraviolet component. For the elimination of ultraviolet radiation from daylight plastic filters in sheet or varnish form are widely used. These filters are not permanent in any climate, and it has yet to be seen whether the excessive heat and humidities of the tropics render their use impracticable or not. The removal of ultraviolet radiation, however, is only half the battle, and intense visible light can be equally damaging in the tropics. The recommended maximum levels for illumination in museums and galleries should be followed, i.e. Less than 150lux for oil paintings and less than 50 lux for specially sensitive material such as water-colours and textiles. For the maintenance of these safety levels extra sensitive objects can be placed in more sheltered positions. Figures show arrangements for baffles, louvres or >brise soleil. Brise soleil should normally cut off sunlight about 45° elevation.