An in-depth examination of Substrate Materials and the relation to both external material frameworks and measured material properties.
https://dev.epicgames.com/community/learning/courses/Emv/unreal-engine-a-deep-dive-on-substrate-materials
This series is by far the absolute best pile of wisdom gems I’ve seen in a good while. Thank you, thank you, thank you. Keep up the great work!
I personally appreciate this level of information, the format, and the fact that it is foundational knowledge; This root-level knowledge is something that we sadly do not see as often “nowadays”, and part of that I think may be due to the general audience: people seem to have shorter attention spans or a lack of patience to sit through deep-dives. People prefer quick bites and magick solution completion buttons 
This series here is definitely going on my list of required or highly recommended reading for any students/disciples. The materials domain just got a big boost on the foundational knowledge front, and for that I salute you Nathaniel!
Funny aside, my name is also Nathaniel, but only when I’m in trouble. Otherwise it’s Nate 