Summary We report an effect of anomalous transparency that is similar to other phantom effects. In an experiment aimed at testing the combined role of motion of the occluding surface and lightness contrast and polarity on the perception of anomalous transparency, we found that transparency is perceived only with low contrast, and enhanced when the occluding surface is moving. A tentative explanation is suggested, based on simultaneous lightness contrast as a segregation factor and on motion as an integration factor, and (...) discussed in light of previous studies conducted in the theoretical framework of Gestalt theories in perception. (shrink)