THE APPEARANCE OF AN OBJECT or material can be described by
its color and gloss characteristics. Like color, gloss can be
subdivided into several aspects depending on viewing conditions.
In 1937, Richard Hunter identified five aspects of gloss
[1] and the functions of reflectance by which they could be
evaluated. Latest studies by K. Lex [2] expanded Hunter's
gloss terms and divided them into two groups. One group is
based on visual observation with the eye focused on the
surface of the material (Fig. 1). For the other group, the eye is
focused on the image of the object reflected by the material
(Fig. 2). However, experience has shown that no single objective
measurement of gloss will provide perfect correlation
with the integrated subjective appraisal of glossiness that the
eye so quickly renders. For this reason, the gloss evaluation
requirement of an object or material should first be examined
and the most useful gloss measurement aspects then selected.