Volumetric Symbol

A small three-dimensional object used on a tactile or audio-tactile map to represent a category of place or facility — for example, a distinct shape for a restroom, elevator, information desk, or exhibition entrance. Research on tactile cartography has shown that blind map users identify and memorise volumetric symbols more reliably than 2D raised icons, because each symbol has a unique silhouette and can be recognised by hand-scanning without relying on legend lookup. Volumetric symbols are typically produced by 3D printing and sit above the base relief of the map surface so they are immediately distinguishable from paths and walls.