VRayToon only provides outlines. You need to use VRayToonMtl or another cartoon-style material (for example, using falloff maps, etc., or other third-party material plugins).
VRayToon does not work properly with objects that have their Cast Shadows property turned off.
The quality of the lines depends on the current settings of the Image sampler.
In order to use VRayToon simultaneously with VRayAerialPerspective, you have to put the VRayAerialPerspective on the top of the atmospherics effects list.
