Objects such as manufactured goods or articles, works of art, media such
as identity documents, legal documents, financial instruments,
transaction cards, other documents, and/or biological tissue are sampled
via sequential illumination in various bands of the electromagnetic
spectrum, a test response to the illumination is analyzed with respect to
reference responses of reference objects. The sequence may be varied. The
sequence may define an activation order, a drive level and/or temperature
for operating one or more sources. Illumination may be in visible,
infrared, ultraviolet, or other portions of the electromagnetic spectrum.
Elements of the evaluation system may be remote from one another, for
example coupled by a network.