What it is: A neon crackle top coat for creating gorgeous nail art effects in minutes. What it does: Create gorgeous neon nail art effects using these innovative new crackle polishes. Simply apply crackle over your favorite nails inc. polish and watch the magic happen-your base color will appear through the crack. Crackle is also the perfect day to night effect. Transform the color you have been wearing during the day by applying the crackle top coat. It's so easy to do and looks like you have spent hours creating a design. Experiment with different color combinations at home or on the go! What it is formulated WITHOUT: Parabens. Sulfates. Synthetic Fragrances. Phthalates. GMOs. Triclosan. What else you need to know: Every crackle also needs a base color. It does not work on a natural nail. The polish shade should always be lighter and a contrasting color to the crackle.