A document full of measured metallic specular values and specular brightnesses by Billy Lundevall.
Note that accurate metal values are equally important in both the specular and metalness based workflows. These values are NOT subjective. Metals generally do not diffuse and absorb all light not being directly reflected. The diffuse color can safely be set to pure black in all cases.
Multiple values mean multiple sources/measurements. Multiple measurements with very similar results mean that the values are more likely to be accurate and are more reliable. Hex values represent reflected color and brightness, “N” is the refractive index and “K” is the extinction coefficient. N and K rarely play a part in real-time rendering and can be ignored for game asset use.
It’s still work in progress and incomplete, so you can share any additional information with Billy to develop this awesome document.
Author: Artyom Sergeev