Markings, such as designs, writings, diagrams, and depictions, are expressive and communicative human artifacts. The conventional assumption that findings from the study of the visual perception of markings-in particular, of pictures-can be generalized to real-world perception is examined and found to be false. The processes involved in the visual perception of the world and in the visual perception of markings differ in significant ways, and generalizations from one to the other must be undertaken with caution. The visual perception of markings is an identifiable and separate area of study. Implications for a general theory of the perception of markings are examined, and the perception of markings is contrasted with real-world perception.