GLOSS

Gloss is often described as the attribute responsible for the shiny or lustrous appearance of a coating. The gloss level of a coating is based on the pigment level in the paint. High pigment levels provide a flatter, rougher finish. Lowering pigment levels increases the gloss of paints.

Gloss is a measurement of the light reflectance of a paint surface. In gloss measurement tests, a beam of light is directed toward the test paint surface at a certain angle from the perpendicular. The percentage of the beam that is reflected at the same angle is measured by a photocell. Two standard angles are used: 60° for general gloss readings; 85° for sheen readings.

Completely specular light reflection (perfect gloss) would be 100%; completely diffuse light reflection (mat or dead flat) would be 0%.

The classification of paints according to gloss ratings depends on the ability of the surface to bounce back varying amount of light beamed on it, and these readings show the relative reflectability of the coated surface as compared with a smooth, flat mirror.

TYPE DESIGNATION 60° GLOSS RANGE* 85° GLOSS RANGE** 

Flat 0 - 5 0 - 15

Eggshell 5 - 20

Satin 15 - 35

Semi-Gloss 30 - 65

Gloss 65 - 100

* Designations and gloss range as outlined are only general references. The above gloss ranges have been developed by the Consumerism Subcommittee of the NPCA Scientific Committee, based on Test Method ASTM D-523.

** Flats and Eggshells can also be measured by an 85° gloss (or sheen) reading.