The appearances of colored objects depend not only on their spectral power distributions, but also on their temporal and geometric surroundings, and on their surface properties. These latter characteristics include: successive contrast, simultaneous contrast, assimilation (sometimes called the spreading effect), gloss, translucency, and surface texture; these characteristics can often have a profound effect. Successive contrast can result in significant changes in lightness and color balance when shotchanges occur in motion-picture films and in television. Simultaneous contrast often has appreciable effects in the design of clothing and documents. Assimilation can alter the appearance of colors in signage, woven fabrics, and tapestries, for instance. The presence or absence of gloss is an important feature in industries such as ceramics, paper-making, and paint production, and can affect not only the apparent color, but also the apparent shape, of an object. Translucency has been found to be an important property in the foodstuff industry, being one of the factors affecting consumers' perception of quality. Surface texture can affect the recognition of objects very considerably; the difference, for instance, between a woven fabric and a metallic automobile finish is recognized very largely by their different surface textures. Although these effects are well known, they are almost entirely lacking any agreed quantitative measures or standards, and this is in spite of their great importance. Some suggestions are made for the way in which such measures might be provided.