How is gloss measured?

Gloss is measured by shining a known amount of light at a surface and quantifying the reflectance. The angle of the light and the method by which the reflectance is measured are determined by surface and also aspect of the surface appearance to be measured.

Different aspects of the gloss of a surface are described by Hunter.

(1)
Specular Gloss

The ratio of light reflected at a specified andlge to the incident on the surface at the same angle on the other side of the surface normal.

(3)
Contrast Gloss (also called Lustre and Haze)

Gloss at grazing angles of incidence and viewing
Ratio of Specularly reflected light and that diffusely reflected normal to the surface

(4)
Absence-of-bloom

A measurement of the absence of haze or a milky appearance adjacent to the specularly reflected light

(5)
Distinctness-of-image

Sharpness of specularly reflected light.

(6)
Absence of surface texture gloss

Perception of surface soothness and uniformityOverall visual assessment

Hunter’s 6 ways to describe gloss.