Details:
Summary:
Gloss has a profound impact on the quality of printed matter. The manufacturing of the substrate and the printing process result in varying amount of gloss from the print. A glossy print with a smooth surface give a high degree of reflection in a relatively narrow specular sector. This contributes to the observed density range and is usually regarded as beneficial from a qualitative perspective. On surfaces that are less smooth, such as newsprint, the print quality is very dependent on the way gloss is angularly distributed. From the measurements it is clearly seen that gloss can be observed at different scales. The fibers themselves as well as the filler and surface material reflect with different characteristics. This paper is based on 360 degree angular measurements with a geometry of 60 degree illumination and zero degree detector. The specimen is placed in the instrument on a moving stage. Mechanically moving the specimen relative to the light source and digitally restoring the geometry create an impression of a moving light-source. In this paper we will focus on the gloss measured on a very detailed level (micrometers) as points of high reflection.