Hi there!
Here is my current progress (on the high poly set for my fat headed pieces!) with the newly added wooden board and the marble tiles! For the black squares, I used a wave texture with an RGB curves modifier on the output. This allowed me to make the generated patterns way darker on some part of the histogram and white on a tiny fraction of the histogram. I could get a dark grey marble effect with it The output is then connected to both the base color and roughness of the material as shown in the course. Hope you like it!
EDIT: updated materials in the thread below
If anyone is interested, here are the settings I used for the grey marble.
Feedback are more than welcome!
Cheers
Nicolas