This International Standard is one of a series of standards dealing with the sampling and testing of coating materials such as paints and varnishes, as well as coatings prepared from them.
It specifies a test method for measuring at 20° the reflection haze of paint coatings.
The use of this geometry means that the method is closely related to the measurement of specular gloss at 20° in ISO 2813. The application of this method is intended to give improved differentiation between high-gloss surfaces, for example in the field of assessment of dispersion characteristics. The method is therefore a useful complement to ISO 8781-3 which uses specular gloss measurements.
For decorative coatings (e.g. automotive coatings), reflection haze is also an important criterion in evaluating the quality of the coating, in addition to colour and specular gloss.
The results obtained often depend on the following properties of the paints:
a) the binder system used and the composition of the paint;
b) the wetting and dispersing properties of the pigments;
c) the method of application;
d) the orientation of the test sample with respect to the plane of measurement.