A process for producing a low-visibility retroreflective visual tag, which
can be used to identify and/or determine the position of an object. This
process involves placing an infra-red-blocking material over a
retroreflective substrate to form the low-visibility retroreflective
visual tag. This infra-red-blocking material is placed so as to form a
pattern, which becomes visible to an infrared sensor when the
low-visibility retroreflective visual tag is illuminated by an infra-red
light source.