|Ah, the wonders of color-correction.|
Private Reserve's Ebony Blue is a pretty difficult color to explain. It's a dark teal, but a lot of the time (especially in wet pens) it ends up being almost black. If you hold it up to a light, though, it has a red sheen around the edges of your letters, especially in places with more ink.
I put this in my Haolilai 850 - which is supposed to have a fine or medium-fine nib, but I accidentally pressed down on the nib while cleaning and it turned into a medium - and it really does not like to feather. You can probably find it feather sometimes, especially on cheap-o printer paper, but otherwise, you should be fine.
The ink is only somewhat waterproof. When I conducted my test, a majority of the ink lifted, but you can still see green-gray remains. It's still mildly legible. However, when I conducted a drip test followed by a soak test, the letters are almost gone; still there, yes, but you're going to be hard-pressed trying to read it.
I doodled with this color a lot. It's just incredibly fun to play with, for whatever reason. I like how it's dark, yet it has that tinge of color to it. Sometimes you want a dark color to play with, and black is too boring after you use it for a while.
You can purchase 50 ml. bottles of Ebony Blue at The Goulet Pen Company for $8.00.