This is a really good point to make, a lot of what you are going to do for a prop is dependent upon what your target output is. If all you want to do is make a render out of marmoset then thats fine. But if your target is a game engine if it doesn't look right in your target then you've lost the plot so to speak. PBR is a…
In the context of PBR texturing (with the metalness workflow) the phosphate coatings aren't pure metals but they can have visual properties similar to metals so they'd fall into the metalloid category. A lot of stuff is still approximate and there can be contextual differences so it's important to experiment with your…