Revealing visual attributes
An artwork may be regarded as an artefact that has been crafted to interact with light. An artist who applies paint to canvas is adding pigments, which are substances that have the property to absorb select bands of the spectrum of incident light, and in this way to modify the spectrum of reflected light. There are techniques of application to further modify interactions with light, such as impasto, which gives texture to the paint layer, and the addition of glaze to the paint surface to affect how light is scattered upon incidence. In another medium, the reason why sculptors have such reverence for marble is because of the range of control that it enables them to have over how light is reflected at the surface. Roughly tooled, marble has a textured opaque surface that can generate strong light and shade patterns. It can be smoothed to a diffusing surface that gives softly graded shading patterns, or it can be polished to an opalescent surface that shows specularly reflected highlights. The long periods of studio work that art students undergo are largely concerned with developing the skill to manage their chosen medium and to control its interactions with light. For artworks to be effectively displayed, the lighting must have the potential to reveal the visual attributes upon which the artwork depends. Lighting for art requires a lighting designer who has understanding of art media and how its interactions with light enable visual attributes to be revealed.