Definitions & Viewing Angles That Describe Finishes
A 60º viewing angle looking at a finish. The most common viewing angle used by the coatings industry to describe the various levels, from flat to high gloss. The gloss of a surface is described by a number based on the reflection of light from the surface that is independent of colour. The higher the number, the ‘glossier’ the finish. ASTM method D523 outlines the procedures for performing the test.
An 85º viewing angle looking at a finish. It is a very high angle view in order to discern the lower gloss levels. At about the mid-range in gloss levels, it is difficult to use the eye to gauge sheen level, so lab instruments are required.
NOTE: Gloss and Sheen are measured by a glossmeter. The values expressed in Gloss Units (GU), and are based on a highly polished reference black glass standard with a defined refractive index having a specular reflectance of 100GU at the specified angle. 0 GU being perfectly matte and 100 GU being perfectly ‘mirror-like’.