I am truly in love with this primer. NARS claims that this "Extends the wear of eyeshadow, eyeliner, and eyebrow pencil. Maximizes color intensity". My oily lids could not agree more.
I literally wore this to the beach in 95 degrees, humid weather, went to a friends house after, and went to eat. By the time I got home, my shadow looked as good as it did when I first left. After using this primer for a year I never put it to the test quite like I did that day and I just knew I will never buy a different primer ever again. (I've tried Urban Decay Primer Potion and I had creases after a few hours)
This primer applies white, but once you blend it out it turns clear
To show the difference between having nothing and having NARS Smudge Proof underneath a shadow, I used the eyeshadow Humid from MAC.
Left | No Primer Right | With Primer
As you can see without the primer, it seems more dull and is not as intense as it is with the primer underneath.