The illustration characteristics of 221 visual representations (VRs) of submicroscopic particles in nine Greek secondary chemistry school textbooks from the last three decades were analyzed. This analysis was done to develop a taxonomy that could help science teachers and curricula designers evaluate the efficacy of such characteristics on student learning. The sample was quantitatively divided into three distinct time periods and analyzed qualitatively using the phenomenographic method through an inductive approach. The "unit of analysis" was every VR of submicroscopic particles together with its caption. Qualitative analysis revealed characteristics such as the type of VR, the way of expression, the signs used, the dimensions represented, the text included, and the complexity of the VR. Quantitative analysis revealed the effect of time on the characteristics. The taxonomy provides an integrated view of VRs illustration characteristics that could help in realizing the multiple ways in which the meaning of a VR could be interpreted, whereas it can also contribute to future appropriate design and use of such VRs toward a better science curriculum.