Which technique is used to enhance nail polish durability?

Using a top coat is an essential technique for enhancing the durability of nail polish. A top coat serves as a protective layer over the nail polish, sealing in the color and providing a barrier against chips, scratches, and wear. This additional layer helps to maintain the polish's glossy finish and can extend the life of a manicure significantly.

In contrast, applying only a base coat does not provide the same level of protection for the polish itself, as the base coat is primarily designed to protect the nails and help the polish adhere better. Skipping the top coat completely would lead to a shorter lifespan of the nail polish, making it more susceptible to damage and fading. Applying multiple colors without a proper top coat can result in a beautiful design but does not contribute to the overall durability of the manicure. Therefore, using a top coat is the most effective method for ensuring that nail polish remains intact and visually appealing for a longer period.