"Fine! When you only use eyeliner, what do you have under then? Are you still using eye primer on the eyelid without wearing eyeshadow? Or do you only have it where you "clicked" green? What do you have to wonder about having the eyeliner in place, especially if you are going to soot it? :) ”
On the particular make-up that you commented on, I have not used eye shadow primer under, only foundation. But it's just to put sustainability to the test properly, review nerd as you are :)
This is because an eyeshadow primer also makes eyeliners more durable! Oily eyelids can cause the eyeliner to smudge around the eye, even if it is a waterproof eyeliner (waterproof is not oilproof), and therefore the eyeliner becomes more durable with primer because the eyelids are kept matte.
And since it is important to saturate the eyeshadow primer properly with eyeshadow, so that it is fixed and stops being moist, I usually just dab on a little powder instead if you do not want eyeshadow.
Eyeshadow primer + powder is also a good idea if you have problems with the mascara smearing on the eyelid / brow bone during the day, because it is also often due to oily eyelids.
In other words, eye shadow primer + powder (if you do not want eye shadow) is never a bad idea! :)