The Toon ramp node controls the amount of detail in toon shading. It provides the mapping positions for a range of colors to the Toon material. The representation of the surface or Volume properties of an Object’s DiffuseAmount of diffusion, or the reflection of light photons at different angles from an uneven or granular surface. Used for dull, non-reflecting materials or mesh emitters. or SpecularAmount of specular reflection, or the mirror-like reflection of light photons at the same angle. Used for transparent materials such as glass and water. channels and the resulting color range is based on the hue set by that channel, respectively. You can add more positions to increase the number of colors in the range. The Toon ramp is applied to a Toon material's Toon Diffuse ramp or Toon Specular ramp.
Figure 1: The Toon ramp applied to the Toon Diffuse and Toon Specular Ramp inputs