3D model of Streptococcus salivarius. Model size: 1.6 cm cell diameter per cell. The number “12” is also printed on the model which enable the participant to match bacteria and name in the context of multiple bacteria printed at the same scale. A scale of 20,000× was chosen to (1) enhance visual and tactile aspects of printed-model handling and (2) enable comparison of size and shape within the mammalian microbiome, with a focus on the human microbiome.

For printing strategy details, see manuscript at https://doi.org/10.1525/abt.2021.83.3.188