RSpec is the peak reflectance measured over a very narrow angular band in the specular direction (+/-) 0.0991º.
RSpec is very sensitive to any texture that is present on a surface. This texture or waviness acts as a concave or convex reflector that deflects light around the specular angle. When RSpec is equal to the gloss value the surface is smooth, as texture increases the RSpec value decreases.
![](https://www.rhopointinstruments.com/wp-content/uploads/2022/03/orange-peel-300x156-1.png)
![](https://www.rhopointinstruments.com/wp-content/uploads/2022/03/no-orange-peel-300x154-1.png)
The diagram above shows the same coating applied to two panels, the first has orange peel/waviness present due to the incorrect application setting on the spray gun.