identification of a method of gloss measurement using a specified angle with assigned apertures
ISO 2813:2014(en), 3.2
gloss
optical property of a surface, characterized by its ability to reflect light specularly
Note 1 to entry: Examples of degrees of gloss are high gloss, gloss, silk gloss, semigloss, satin, matt, and dead matt.
[SOURCE: ISO 4618:2014, 2.132]
ISO 2813:2014(en), 3.1
gloss value
ratio multiplied by 100 of the luminous flux reflected from a specimen to that reflected by a glass surface with a refractive index of 1,567 at a wavelength of 587,6 nm in specular direction for a specified reflection angle and specified aperture angles of light source and receptor
Note 1 to entry: The gloss value is indicated in gloss units (GU). It is not permitted to interpret and express gloss values as “% reflection”.
Note 2 to entry: Gloss values measured on coatings are expressed rounded to the nearest integer (without decimals).
Note 3 to entry: To define the gloss scale, polished black glass with a refractive index of 1,567 at a wavelength of 587,6 nm is assigned to the value of 100 for 20°, 60° and 85° geometries.
Note 4 to entry: A glass surface with a reflective index of 1,567 at a wavelength of 546,1 nm (which is the central wavelength of the spectral luminous efficiency function) may be used.
Note 5 to entry: The gloss value is influenced by the surface characteristics, e.g. roughness, texture, structure, of the sample.