SignBase is an open access database for geometric motifs on mobile objects in Prehistory. Its focus lies on finds of the Eurasian Paleolithic and African Middle Stone Age. In these time periods, geometric motifs – also referred to as signs, patterns, or marks – are abundant in parietal art as well as on mobile objects. The term “geometric” denotes simple non-figurative forms such as dots, lines, and crosses, as well as more complex patterns. This includes frequent semi-abstract depictions such as vulvae, but excludes figurative depictions of animals, humans, etc. Decorated mobile objects are mostly made of osseous material, like ivory, bone or antler, while also featuring other organic and inorganic materials.