Gloss, as has long been known, is a far more complex visual concept than the present methods of instrumental gloss evaluation are able to characterize. The instrumental analyses are either highly over-simplified (standard gloss meters) or over-simplified but with results still difficult to interpret (goniophotometry). The dimensionality and power of the directed reflectance information measured by existing tools is lower and less expressive than the information gained from a direct visual examination of a surface. The purpose of this paper is to review important gloss measurement issues, in the context of perceptual evaluation. This work gives a background for defining necessary requirements for an evaluation system that can reveal the perceptually relevant gloss features of the surface measured.
Mikael Lindstrand, "Instrumental Gloss Characterization – In the Light of Visual Evaluation: A Review" in Journal of Imaging Science and Technology, 2005, pp 61 - 70, https://doi.org/10.2352/J.ImagingSci.Technol.2005.49.1.art00009