This liner has really great potential, it's not super expensive for a liquid pen and is fantastically easy to use, but it just dries out so disastrously quickly! Within about two weeks of using this liner it had dried out to the point where it was practically unusable - to get any product out at all I had to apply so much pressure that I lost all precision... which is kind of the whole point of liquid pens!!
I also didn't find it to be a particularly rich black, which is definitely my preference.
Don't waste your time, spend the extra $12 and get the Stila Stay All Day.
I bought this after hearing an endless string of great reviews. It is a pen format, which makes it really easy to use. Uncap the lid and you see a small flexible felt tip style nib, which makes drawing a precise line easy.
I prefer to use the tip and the flat edge of the nib towards the tip for the most precision. You do have to be a bit careful as the nib widens quite a bit towards the base and will produce quite a thick line. You could use this part to make a wing quickly but I usually just line the top lashes without a wing.
Now for why I gave it a 2/5 stars: it dries up really quickly. Far too quickly. I probably only had two months max use out of this, and I didn't use it everyday. Towards the end it became very greyish also, not like the nice dark black it was at the beginning. Not sure if I got a dud or not but I'll stick with pot format liquid liners and gel eyeliners for now.