Trying to create a glossy black plastic

Question

I am trying to recreate the attached material, which is a carbon fiber injection molded composite. I've done a lot of research on Levels and shader nodes, and this is my best approximation of the material so far. I'm fairly happy with the texture (I would love to get it more accurate), but my primary issue right now is recreating the glossy sheen on the material. I've tried mixing a glossy shader node in the last step, I've tried to adjust the fresnel to give more weight to the glossy shader in that section, I've tried to adjust the principle shader with a higher specular, sheen, metallic, and clearcoat, but nothing seems to give any sheen to the plastic in the final render. Any thoughts or advice is welcome.

Answer 1

I think your graph may be too complicated for its own good, so to speak. What I mean is that I think you can forgo a lot of the complex shader mixing and go with something simpler. Since you are using a Principled BSDF (which is basically every shader in one), you can just stick to it alone.

That being said, a common way to get a Roughness map (for textured plastics) is to invert the Bump map, and then adjust it to your liking. The reason for this is that you can imagine the outermost of the "bumps" has encountered the most wear , and therefore has become a bit shiny. You can control its effect rather well with a ColorRamp and a Bright/Contrast node (Note in the image below, I inverted the sliders on the ColorRamp to invert the image, hence why there is no invert node).

You can leave the metallic at 0 because it is a plastic (non-conductive), but I find plastics like that usually benefit from a very small amount Subsurface Scattering (because the thinnest parts let some light through).

Lastly, I think you can forgo the Displacement altogether, as the value you are using for the Noise is high enough that the displacement effect will need an enormous amount of subdivisions to display properly (if using cycles), and will not make much visual difference in eevee, and will likely only act to slow down the shader graph and the render.