How to measure coat gloss: let's discover the surface gloss test
How to measure coat gloss:
let's discover the surface gloss test
13 July 2021
Compliance with gloss parameters is often essential when painting, which is why it is essential to assess it with safe, standardised and easily replicable tests.
Gloss is one of the key aesthetic characteristics of surface coatings, on a par with the color itself. For this reason, measuring the gloss of the coating is essential for assessing the appearance of a surface-coated item.
Using a special instrument, called a gloss meter, it is possible to identify the degree of gloss achieved by the coating, in order to understand whether it meets expectations.
It should be borne in mind that visual appearance can determine people’s perception of a product, and that this perception is subjective. In order to get around this “personal” component, one of the measurement parameters used to define and quantify the overall visual quality of a product is gloss. For this reason, it is essential to evaluate it with safe, standardized and easily replicable tests.
Glossiness is measured by aiming a beam of light at a constant intensity, at a fixed angle, at the surface to be evaluated and then monitoring the amount of light reflected from the same angle. This specular reflectance is measured using the aforementioned glossmeter. It must be kept in mind that different surfaces require different reflection angles.
Gloss is classified as matte, semi-gloss or gloss, and the unit of measurement that governs it is called Gloss Units (GU). The process involves the detection of 3 different angles of reflectance, at 20, 60 and 85 degrees.
The rating scale for this parameter goes from a minimum value of 0, indicating a totally non-reflective surface, to a maximum value of 100, indicating the highest possible gloss.
The standard governing this test is ISO 2813.