The most important property for this material is its Reflectance, which is the only channel we will use in its creation. All other material channels will remain disabled.
The 1st Reflectance layer
A good paint job generally has a base coat. Rename the Default Specular layer to Layer 1 and set the mix mode to Normal. This color information can be supplied by using the Color channel but the Reflectance channel offers layer types that are specially designed for creating extremely diffuse surfaces. The shading Types are the same as those found in the Color channel. Lambertian (Diffuse) is for smooth surfaces and Oren-Nayer (Diffuse) is for rough surfaces. Of course we will use Lambertian (Diffuse) for our car’s lacquer. Since this type creates a diffuse spread with an endless range, the Roughness value will automatically be disabled. The Roughness value is available for the Oren-Nayer (Diffuse) Type in order to soften its shadows - but even if its value is set to 0%, the diffuse effect is so strong that no noticeable reflection or highlights can appear. The Specular Strength and Reflective Strength values are used to define the surface shading. Reflection Strength and Specular Strength values of 30% should add enough brightness to the paint. The color is defined in the Layer Color menu. Define a dark green for our example.
In the image above you will also see that the Layer Fresnel settings have also been modified. This will darken the brightness of the shading at those locations at which the surface lies perpendicular to the angle of view. This variation in brightness gives the lacquer additional depth. Set Fresnel to Dielectric and set its IOR value to 2 to reduce the contrast between the surface’s center and its edge.
The 2nd Reflectance layer
This layer (click on Add to create a new layer (Layer 2 and set its mix mode to Add) lies over the first layer and contains the metallic particles. Set its Type to Ward, which will generate a diffuse spread somewhere between the Beckmann and GGX types. A Roughness value of 60% will expand the region within which highlights will be captures. Reflection Strength and Specular Strength values can each be set to 20%. In the Layer Color menu, define a green that is lighter than the base layer’s color.
The actual metallic effect is created when the highlights and reflections are restricted to tiny particles between which the base color can be seen. This can be simulated using a mask. To do so, load a Noise shader into the Texture field in the Layer Mask menu. In the Noise shader, select a high-contrast structure such as Cell Voronoi for the Noise setting and reduce its Global Scale to 2% to create a very fine grain.
The image below shows our material’s current state. We still need to add a sharp reflection, which will be created by the 3rd layer. The result of this is shown at the right of the image below.
The 3rd Reflectance layer
This last layer (set its mix mode to Normal) will be used to create a clear coat effect. It will be much simpler than the previous two. Set its Type to Beckmann and set its Reflection Strength to 80%. Set its Roughness, Specular Strength and Bump Strength values each to 0% to create a prefect reflective surface. Set Fresnel to Dielectric in the Layer Fresnel menu and set Preset to Glass. That’s it.
Drag the material onto the Lacquer object in the Object Manager. The material will fit the car body automatically without using any projection. This is possible because the material’s noise structure is so fine. The image below shows the final result.