What does 'matting effect' mean? Like color, both matting and gloss are subjective impressions that are identified by our senses. Light is reflected from an even surface into our eyes and we categorize it according to its gloss. (White)

Strictly speaking, only part of the light falling upon a surface is directly reflected, the rest passes into the paint film and is internally scattered and absorbed by pigments and the substrate. (dark yellow)

The intensity of reflection depends on the degree of surface-smoothness. Mirrors, for example, are recognized as high gloss surfaces as they reflect light with high clarity. In contrast, when micro-rough paint films scatter light, only a reduced amount of light is reflected. In this instance a yellow matt covering appears. 

The conditions to obtain a perfectly matted effect are to scatter the incoming light. This means diffracting the directed light that illuminates the substrate. Otherwise, a substrate that would perfectly transmit the light would produce a gloss aspect.

The micro-roughness of the paint film surface is the reason why the light is scattered in a way thatresults in a matted surface.