Perceptual Qualities of Optically Mixed Materials

We present a novel setup in which real objects made of two different materials can be mixed optically in a linearly weighted manner. We conducted a psychophysical experiment in which observers rated optical mixtures of the three combinations of glossy, matte, and velvety green birds. The observers rated the materials on four scales: matte–glossy, hard–soft, cold–warm, and light-heavy. The judgments were found to be consistent and varied systematically with the weights of the contributions.