The Nature Strong Nail Polish Base and Top Duo Pack helps to care for the nails while enhancing colour longevity. The plant-based set by OPI aims to deliver a high-shine manicure that lasts for up to seven days, and leaves nails feeling stronger. Vegan. Set Contents: Nature Strong Botanical Base Coat 15ml Powered by gentle skincare ingredients, this multi-purpose base coat smooths the nails, helping to prepare for colour application. Nature Strong Top Coat 15ml Protect your manicure with this quick-drying formula. The top coat works to minimise the risk of chipping and fading.