I've never really been able to get on board with pen liners. I love the idea, but the reality is that I find them awkward to use. Even the more flexible felt tip pens don't seem to be quite flexible enough, causing a bit of dragging when applied. My twitchy eyes don't do well with it. So for the most part I avoid reaching for the pen option and instead grab for my trusty gel pot and fine liner brush combo.
A few weeks ago I was watching Tamira's 5 Drugstore Favourites video and she mentioned that she found the Physician's Formula Lash Boosting Eyeliner and Serum to be reminiscent of the Kat Von D Tattoo Liner. At half the price of the Tattoo Liner I thought it was worth a shot. As Tamira noted, it doesn't have the same colour pay off (you will need a second coat), however what it does have is the same fantastic tip. Rather than the classic felt tip that comes with most pen liners, the Physician's Formula option contains actual hairs that come to an incredibly fine and precise tip.
The benefits of this design are two fold. One, you have more control over making your line as thin as you want, as well as making the tip of the flick as fine as you want. Two, you don't get any awkward dragging over your lash line like you do from a felt tip. There were no twitchy eye moments for me here. Additional points for the fact that is sets like a rock and contains a lash boosting serum. So if you're looking for an affordable drugstore option of this new generation of pen liners I'd say that it's definitely worth taking a look at Physician's Formula. If you can't stand having to go over your liner a couple of times and you've got some cash to spend, it's probably best to head straight to a Kat Von D stand.