To determine the correct gloss measurement angle, gloss is first measured at a 60° angle:

• If the result is between 10–70 GU, the object in question is considered semi-gloss and the 60° measurement angle is appropriate.
• If the result is greater than 70 GU, the surface is considered high gloss and should be measured with the 20° angle.
• If the result is less than 10 GU, the surface is considered matte and should be measured with the 85° angle.

Each angle is suited to different levels of gloss:

• 20°: For high-gloss surfaces. It provides a higher resolution measurement to differentiate between very glossy surfaces.
• 60°: The universal measurement angle, used for a wide range of gloss levels.
• 85°: Used for low-gloss surfaces, offering better differentiation in the lower gloss range.