Scientific language is multimodal, that is, it makes use of several modes of communication to develop scientific knowledge. Among them, and of particular interest for this research, are the inscriptions, which fit into the visual modes of communication and are the material visual representations created inherently in scientific tasks, such as graphs, photographs, tables, equations, maps, schemes, etc. Given the importance of the inscriptions both for science communication and science teaching, as well as their strong presence in textbooks and the classroom, the fact that students find it difficult to use and interpret them has drawn the attention of educators, who have focused their studies on understanding the factors that interfere in producing adequate readings of inscriptions and drawing up proposals that develop students' graphicacy. This would be the relative knowledge to deal with visual modes of communication, especially inscriptions. In this perspective, this study investigates the extent of Chemistry undergraduates' graphicacy in a science communication course, while giving oral presentations produced from original research articles. Researches carried out by Wolff-Michael Roth et al. was adopted as a theoretical reference during the analysis, which consisted of: classifying the functions of the inscriptions in oral presentations into decorative, illustrative or complementary; describing the production of meanings from the inscription readings using a Semiotic Model to the Reading of Inscriptions; and classifying types of inscription readings into competent, transparent, or problematic reading. It can be observed that the production of meanings is related to the function of the inscription, which decorative and illustrative ones require a more active participation from the audience. The complementary ones depend more on the semiotic resources offered by the student giving the presentation. Based on this, interpreting the inscriptions can be described in terms of the elements and processes of the Model, which reveals whether or not what was made available was adequate for the production of meanings. Concerning the extent of the graphicacy of the groups investigated, one of them can be found in the analytical dimension, in which the students see and use the inscriptions as scientific data. It is worth mentioning the wide range of contact with several types of inscriptions and the development of various skills related to graphicacy. The other two groups are in the elementary dimension, in which the students use and see the inscriptions primarily as illustrators of scientific knowledge, having restricted contact with the various types of inscription. In this case, the development of few skills related to graphicacy and a production of meanings can be observed that does not reveal the role of inscriptions for science. Competent reading was predominant in all presentations, which was expected and appropriate due to the context and communicative nature of the oral presentation. A new type of reading for inscri...