Perceptual portraits represent people in an unconventional style. The portraits themselves are not always easy to discern—the viewer needs to apply the power of perception in order to extract the facial features from the design that carries them. The aim of perceptual portraits is both artistic and historical. They generally consist of two elements—the portrait and some appropriate motif. The nature of the latter depends on the endeavors for which the portrayed person was known. In some cases the motif is drawn specifically to display a phenomenon associated with the individual, in others it is derived from a figure or text in one of their books, or apparatus that they invented. The portraits and motifs have themselves been manipulated in a variety of ways, using graphical, photographical, and computer graphical procedures. The illustrations often require some eVort on the part of the viewer to discern the faces embedded in them. I believe that such perceptual portraits both attract attention and engage the spectator’s interest to a greater degree than do conventional paintings, prints, or photographs. It is hoped that this visual intrigue will enhance the viewer’s desire to discover why particular motifs have been adopted and, in turn, to learn more about the persons portrayed: it is intended to be an instance of art serving science. Further examples can be found in Wade (1990, 1995).