I am developing a moonbase and I am looking for dramatic contrast in the light. Inside the base, I want rooms that are normally lit with a door frame and the next room absolute dark. What surface would be the best for the dark rooms? I am looking for surfaces with a dark matte aspect. Thanks
If you want to have absolutely no light interacts with the surface, just unplug everything from the material output node.
For a Lambertian surface rather than a completely flat one, you could use a Diffuse shader set to completely black.
If you wanted it have a combination, you could mix the Diffuse with just... nothing... and then adjust mix factor to control the blending.
A Material Output Node with no connected sockets
No light can escape the surface.
Not very realistic unless you're rendering a black hole. But you did ask for the most non-reflective surface. ;-)
Material using disconnected sockets - the black circle is completely unaffected by the light source (sphere)
A black Emission Shader
This has the same effect as a disconnected Material Output Node - no light reflects from it because this shader is strictly for emission. When the color is completely black, there is nothing to emit.
A diffuse shader with the color set to pitch black should do the trick. As it is a purely diffuse surface it will not reflect any light and therefore the inside of the rooms will appear to be pitch black.
Alternatively, shade the surfaces of the rooms normally and place a light source inside them with a negative emission value to subtract light from them.