I am so glad for this new product from Smashbox. You can use it to turn any eyeshadow into an eyeliner. It comes in a small bottle with a dropper. For use you simply put a drop on the back of your hand, dip your brush in it then into eyeshadow or any powder product of your choice swirl your brush a bit and apply. Once it dries (in seconds) you have a smudgeproof, budgeproof liner that wears basically until you take it off.  I have worn mine up to 12 hours in a very hot and humid climate and it stays perfect.