The "Material Hub" is a C4D plugin (powered by Python) that lives inside your Cinema 4D window (Extensions > Greyscalegorilla > Material Hub).

If you know your way around the Redshift Node Editor, you might ask, "Why pay for materials?"

The primary selling point of GSG Redshift materials is the removal of friction. In high-end rendering, there is often a "setup tax"—the 30 minutes to an hour spent building a complex shader network before you can even begin lighting.