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.

The relevant artifacts come from stratified archaeological contexts and are assigned to the particular techno-complexes. The objects are the core elements of the database, carrying a unique identifier. With this identifier comes information about geographic and archaeological provenience, the type of object and material, size and preservation, literature references, as well as a picture if available. The geometric motifs on each object are described in detail using a specifically developed encoding. The database aims to enable quantitative comparative studies on the development of graphical expressions before the emergence of writing systems.

SignBase gives latitudinal and longitudinal information for each object, and hence allows analyses of geographical distribution and geographic clustering of signs. Densities of sites with geometric signs, or densities of particular sign types give an overview of the abundance and distribution of signs. In the long run, this might be linked to population turn-overs, and respective cultural entities of the Paleolithic.

The meaning of abstract motifs in the Paleolithic is very difficult (if not impossible) to understand. The lack of rich cultural and archaeological contexts often leaves particular signs in a vacuum that only allows for speculation with regards to their function and usage. However, techniques from quantitative linguistics can be used to assess the statistical properties of sign inventories independent of their meaning.