Brand from South Korea: Etude House. Nail Gradation Sponge used to create gradient nails. (Handle Included). How to Use: In the order that you want the gradation to appear on your nails, paint your sponge with all of the polishes. Make sure that the colors overlap slightly. Dab the sponge lightly onto your nail for several times. While dabbing, use a very slight up and down motion in order to blend the colors together. Use a cotton swab dipped in nail polish remover to clean up the mess. Add a layer of your top coat.