Preferred lighting conditions for the display of oil and watercolour paintings

Abstract

The lighting of paintings suffers from the need to meet two conflicting requirements: the visual requirement of the gallery visitor and the conservator's requirement to preserve the works of art. The project explores by experiment in a full-scale mock-up gallery the lighting requirements in terms of three variables: painting illuminance, light source and light distribution within the gallery space. Subjective assessments were made using semantic differential scales and the results were analysed using factor analysis techniques. The findings indicate that a painting illuminance approaching 200 lux was required to give visual satisfaction from an illuminant with a high Colour Rendering Index and a high gamut area: also a degree of non-uniformity in light distribution was preferred. The work recommends that where strict conservation requirements are to be employed, then artificial lighting only should be used but that the galleries should be combined with other spaces lit with natural light, perhaps for the display of non-light-sensitive exhibits.