Chemical structures are among the trademarks of our profession, as surely chemical as flasks, beakers and distillation columns. When someone sees one of us busily scribbling formulas or structures, he or she has no trouble identifying a chemist. Yet these familiar objects, which accompany our work from start to end, from the initial doodlings (Fig. I) to the final polished artwork in a publication (Fig. II), are deceptively simple. They raise interesting and difficult questions about representation. It is the intent of this article to reflect upon molecular graphics.