Despite a growing body of research on multimodal writing, scholars still express a need for formal frameworks for discussing multimodal literacy practices and call for research on multimodality in education that develops a vocabulary to approach multimodal texts in teaching. This study answers this call by presenting an analysis that adds to the field of multimodal writing research, and thus furthers the knowledge of different semiotic potentials of modes in student-produced texts. Drawing on a social semiotic approach to multimodality, a total of 299 texts, written by fifth-grade students from three schools in Sweden and Finland, are analyzed. The aim is to explore semiotic modes used in the student-produced written texts. The guiding research questions are: (1) What modes are used in the texts, and (2) what meanings are realized through the different modes in the texts. Results showed that six different modes were used to realize meanings in five categories: create representative meaning; visualize phenomena and assignments; foreground important areas; design the text; and decorate the paper. These categories offer a vocabulary that can describe semiotic potentials of the modes and how they realize different meanings in multimodal texts. Such a vocabulary can aid teachers in cultivating, supporting, and assessing students’ multimodal writings that contain multiple modes. From these results, we suggest that acknowledging the diversity of the modes and their meanings in student texts can help raise the awareness of how students also make meaning in modes beyond writing and image.