YSL Aquaresistant Waterproof Mascara Shade 4W Purple is a lengthening and thickening formula. This amazing water resistant formula stays in place and vibrant in water. No smudging and no running. You will maintain perfect eyes in and out of the water. Best to be removed using eye makeup remover. How to Apply: Apply mascara on lashes starting at the base and wiggling want slowly towards the ends. Layer mascara to desired thickness.