Re: What are the options for black rings in a grip?
Check out some of Terry Henson's builds. I believe he uses either Buffalo horn or Water Buffalo horn. Ebony wood is also very, very dark, if not black. Every once in a while some of the pen blank dealers offer bigger diameter acrylics you could turn down.
"Blessed is the fly fisher who's quiver contains grass, glass & graphite custom rods." Book of Rods 3:16