This eyeliner was really great, it far outshone my expectations. Like many people do with new makeup products, I swabbed some on my hand to assess the pigment and consistency. It was very black, which is what I was looking for, and was smooth - so far so good.
Once it set on my hand (after about a minute or two), that stuff was set to be on forever. Rubbing on it with full force with my dry hand or a cloth didn't make it smudge or transfer at all. I tried the same thing with water, and then with soap, then with a cheap makeup remover. None of those made it flinch at all. In fact, the only way I got it off was with some olive oil and a bit of rubbing. For me, that's very good because I often have an issue with my eyeliner trying to transfer. The only liner I've seen to work for me prior to this was Kat Von D's Tattoo Liner, which is rather expensive ($20) and is prone to drying out.
The only downside besides it maybe staying TOO much is this: If you have really oily lids, this may take a bit to set. I used this on a friend who was one of those individuals, and they made the mistake of blinking before it set, and smearing onto the eyelids it went. After it dried, it was there forever, but if you have oily lids, you may want to leave your eye shut for a couple minutes, less you want to smear it and start all over again.