In argument diagrams, perceptual cues are important to aid understanding. However, we do not know what perceptual cues are used and produced to aid understanding. We present two studies in which we investigate (1) which spatial, graphical and textual elements people spontaneously use in creating for-against argument diagrams, and (2) how people interpret these elements to find out one's argumentative position. In the production study, participants were presented with arguments in favor and against a societally relevant topic and were asked to graphically represent the arguments such that their position (for or against) would become clear to a reader. For the perception study, we manipulated the argument diagrams created in study 1 into six different versions by deleting text, graphic cues and color. Participants saw one version of the diagrams; they were asked to judge the argumentative position, and to explain what they based their judgment on. We found that--in spite of individual differences--natural sources were used by all producers, for example by creating a well-formed structure, or by using spatial and graphical elements to separate or highlight arguments. Furthermore, although interpreting the argument diagrams was best done when the combination of text and graphic cues was present, graphic cues alone seemed to be very important for interpretation. We conclude with a cautionary hierarchy of perceptual cues in argument diagrams.