I can’t find where the default Materials folders are located on my PC. I am now using SU2019 and have looked in the Preferences, Files, and checked where the Materials folder is. Yet, when I go there, that folder is empty though in the operation of the program I still have access to them - Asphalt, etc.
You’ll find the shipped material at
C:\ProgramData\SketchUp\SketchUp 2019\SketchUp\Materials
Thank you, thank you, thank you.
I have been pulling what’s left of my hair out trying to find it and suffering with extremely slow W10 File Explorer searches.