How to use Mascara as Eyeliner

I heard through the grapevine that one can use mascara as an eyeliner. I gave it a shot, and was really impressed! The mascara went on in one stroke, and packed a ton of pigment. It didn't budge all day! Anyways, here's how you do it:
1. Get a really small makeup brush. I used e l.f.'s professional concealor brush.
2. Dip the brush into the desired tube of mascara. Make sure you have plenty on the brush.
3. Apply as you would a gel liner
The picture below is of how the liner looks before I put mascara on my actual lashes.