Roughness / Glossiness

The Roughness or Glossiness channel describes a material's surface irregularities and how they affect the reflection of light. See Diffuse vs Specular Reflections for more information.

The channel uses a linear grayscale texture, or a solid grayscale color. Roughness and Glossiness are inverses. That means 100% roughness is the same as 0% glossiness, and vice-versa.