What difference can the human eye see in gloss units?
If two different coatings are measured, how many units of gloss can the human eye detect, and how many units would be considered significantly different?
These detectable differences depend on the gloss level of the sample when measured at 60 degrees, e.g. a 3.0GU difference measured on a very matte surface (maybe 5GU) will be seen by the human eye, but on a higher gloss The difference on the coating (probably 60GU) will be hard to notice.
You can experiment with ways to determine product tolerances, possibly prepare print samples of different gloss levels, you can show the paint to the end user or an in-house "professional"
Another option is to change to a 20/60/85 degree instrument, 85 degree gloss meters are more sensitive to gloss differences below 10 GU @60º, 20 Degrees resolution for high gloss paints (70 GU @60º and above) higher, . The advantage of using all three angles is a greater gloss difference, in our experience a gloss difference of 5 GU is only visible to a trained observer when measured with the correct geometry.
