From NYX’s website:
Apply eyeshadow base to lids, then apply eyeshadows and see the colours pop with vibrant and sparkling luster. Eyeshadow base grabs and firmly holds finely milled powder so the colour in the pot is what ends up on your eyes.

What I liked:
– improves the colour payoff and intensity of eyeshadows
– easy to apply
– the price

What I didn’t like:
– if you have oily lids, eyeshadows will still crease and fade after a few hours of wear
– jar packaging

I’ve been wanting to try NYX Eyeshadow Bases (available in White, Pearl and Skintone) ever since they came out so when I started running low on primers I thought it was finally time to give one of them a go. Because I love my eyeshadows very vibrant, I opted for White. White bases, in fact, apart from making your lids ghastly after application lol, improve the colour payoff of eyeshadows and really make the shades pop a lot more than any flesh-toned primers.