I don't know how practical it would be to make a black, DLC-coated milanese loop.
This mesh is made by running wire though a coiling machine, and then weaving the resulting spiral shape through the loops of the previous wire. The wire is cut off and the wire ends are bent back so they don't stick out. On the best bands, the wire ends are welded for a smoother finish.
If you DLC coat the raw wire, the coating has to survive going through the coiling and weaving process. I don't know if DLC is ductile enough. In any case, the cut ends of the wire wouldn't be coated.
On the other hand, if you try to DLC coat the mesh after it is woven, it will be difficult or impossible to get a uniform coating on the whole surface of each wire.
I find the machines fascinating. For example, here's a machine making a larger, looser mesh:
https://www.youtube.com/watch?v=EEQOAxtLiDg
The machines that make watch bands are similar, just a lot smaller.
Compare this Apple video, starting around 1:57:
http://images.apple.com/media/us/watch/2015/a718f271_b19c_47d8_928d_d108fc5d702a/tour/stainless-steel/watch-stainless-steel-cc-us-20150309_r848-9dwc.mov