I got this in a pack with a pencil eyeliner and a sharpener for two dollars. It's so dark, a true black, and it stays for the most part. I use this to go over my (less impressive) Jordana Fabuliner. Even though it does flake off a little after a while, it'll mainly stay on, until you wash it off (which leaves a bit of residue if you don't wash your face good enough but is easy enough to wash off).
Black liner is very opaque and with a felt tip pen is quite easy to use. I haven't tried the other colors.
For $2 it is everything I need in a liquid liner. I have to remove this with something strong. I use olive oil to take it off. It last all day. I love it especially on my oily lids.