SPECULAR GLOSS OF PAPER AND PAPERBOARD AT 75 DEGREES

This method is for measuring the specular gloss of paper at 75° (15° from the plane of paper). Although its chief application is for coated papers (1), it is also used for a variety of uncoated papers.

This method is suitable for low- to high-gloss papers. For very high-gloss papers such as cast-coated, lacquered, highly varnished (2-4) or waxed papers (5), and high-gloss ink films (6), TAPPI T 653 “Specular Gloss of Paper and Paperboard at 20 Degrees” is preferred. T 480 has been shown to be suitable for gloss measurements of most ink films on paper or paperboard. Differences in the color and diffuse reflectance of these ink films have a negligible effect on measured gloss. For example, when white and black surfaces which are otherwise identical are tested, the white surface will measure less than one gloss unit higher than the black.

This method does not measure image-reflecting quality.