If two different coatings are measured, what number of gloss units would be detectable by the human eye, how many units would be perceived as significantly different?

 

When measuring at 60 Degrees with gloss meter these detectable differences depend on the gloss level of the sample, for instance 3.0 GU difference measured on a very matt surface (perhaps 5GU), would be seen by the human eye but on a higher gloss coating (perhaps 60 GU) the difference would be very difficult to notice.

 

 

The only way that you can determine tolerances for your products would be experimentally, perhaps preparing printed samples at different gloss levels that you can show to end users of your coatings or internal “experts”.

 

The other option is to change to a 20/60/85 degree gloss meter, the 85 degree glossmeter is more sensitive to differences in gloss below 10 GU @ 60º and the 20 Degrees has higher resolution on high gloss coatings (above 70 GU @ 60º). The advantage of using the three angles is that there is more equality to the gloss differences, in our experience a gloss difference of 5 GU, when measured with the correct geometry is just visible to a trained observer.

 

In the market, there are different angles gloss meter, but general popular angle is 60 degree and 20/60/85 degree gloss meter (tri-angle). 3NH offers NHG268, NHG60, etc touch screen gloss meter.