MAC Mixing Medium Eyeliner Ok so holy grail find!! On a whim after seeing a couple of reviews I tried the MAC eyeliner mixing medium to attempt to keep my eyeshadow from creasing. I have very very very oily lids and have suffered with eyeshadow creasing for years. I have tried everything, this lasted over 11hrs. I've never had that happen. 100% worth it! Check my review on makeup alley: suncoast215.