Hotspots on illustrations are typically created with overlays.

An overlay is an invisible field that is laid over the illustration. On this field, the hotspot regions are defined. This technique allows extensive independence from formatting methods.

As a general rule, the overlays are created with an electronic catalog program and are saved in a format that can be read by the catalog program. With DTP or publishing systems the hotspots cannot usually be created, since these systems do not support linking functionality.

Links connect hotspots with locations outside the illustration in the final step.