Specular gloss of paper and paperboard at 20 degrees

This method is for the measurement of the specular gloss of high-gloss papers at 20° (70° from the plane of the paper).

This method is suitable for high-gloss coated, cast-coated, lacquered, highly varnished or waxed papers, and high-gloss ink films. For the measurement of low- to moderate-gloss coated and uncoated papers and low- to moderate-gloss ink films, TAPPI T 480 “Specular Gloss of Paper and Paperboard at 75 Degrees” is preferred. Neither method is a measure of image reflecting quality.

This method is specifically restricted to gloss meters with geometric conditions specified in Section 5.1.1, commonly referred to as converging beam optics. An interlaboratory study conducted in 2015 indicated that statistically significant 20 degree gloss measurement results may be obtained from gloss meters with other geometric conditions, commonly referred to as parallel beam optics.