The Sheen rollout is part of the Generic material's parameters.
See the Coat and Sheen page or the Courseware page for more information.
Sheen
Available only in Advanced mode.
Sheen Color – Specifies the color of the sheen layer. Black color disables the effect.
Sheen Glossiness* – Available when the Surface control option is set to Use Glossiness. Controls the sharpness of reflection. A value of 1.0 means all of the light reaches the diffuse color, whereas when the value is smaller, the cloth material looks glossier. See the Sheen Glossiness example below.
Sheen Roughness– Available when the Surface control option is set to Use Roughness. Controls the sharpness of reflection. A value of 0.0 means all of the light reaches the diffuse color, whereas when the value is higher, the cloth material looks glossier.
Example: Sheen Glossiness
This example shows how changing the glossiness parameter of the sheen layer affects the material. A smaller value makes the sheen layer reflect most of the light. Increasing the value allows more light to reach the diffuse component.
Sheen Reflection = 0.1
Sheen Reflection = 0.3
Sheen Reflection = 0.5
Sheen Reflection = 0.6
Sheen Reflection = 0.8
Sheen Reflection = 0.9
Sheen Reflection = 1
Notes
* – When a Bitmap texture is mapped in this slot, its color space is automatically adjusted. Copy-pasting, replacing or wrapping a texture does not trigger this automatic adjustment. It is reserved solely when creating a Bitmap in the specified material slot.