Beck (1972) published a picture of a vase with and without highlights. The vase with highlights looked glossy. The vase without highlights looked matte. There are two alternative hypotheses concerning the perception of glossiness. One hypothesis is that the perception of glossiness, like the darkening due to contrast, is a spatially local perceptual quality that results from the presence of highlights. The second hypothesis is that the perception of glossiness is the result of a perceptual inference that a surface reflects light specularly based upon the information provided by highlights. The perception of glossiness is the result of both sensations and an inference based on past experience that causes the entire surface to appear glossy. Helmholtz explained the effects of surface texture and finish on the perception of color in these terms (Graham & Brown, 1965). The two hypotheses are examined by studying how the size, brightness, orientation, the placement of highlights, and the intensity gradient on the vase surface affect the perception of glossiness. The rightmost photograph in A of Figure 1 reproduces a digitized picture of the glossy vase in which all highlights were removed. In the left photographs, single highlights are superimposed on the digitized vase pictures. The positions of these highlights correspond to the positions of actual highlights originally on the vase. The vertical and horizontal intensity profiles of these highlights have the shapes of an inverted V and were chosen for computational simplicity. Forbus (Note 1) has shown that the intensity profile of a highlight is not critical as long as it is not discontinuous. The highlights make their surrounding areas look shiny. They fail, however, to make the entire vase look shiny. In B, two highlights are shown. The effects of the individual highlights combine and make the upper part of the vase look shiny. The lower part of the vase, however, continues to look dull. Highlights have a local effect that makes surrounding areas of the vase appear glossy. They do