What is the purpose of using a base coat before applying nail polish?

Using a base coat before applying nail polish serves several important functions, with one primary purpose being to prevent staining of the natural nails. Many colored polishes, especially those that are darker or contain certain pigments, can cause discoloration of the natural nail surface if applied directly. The base coat acts as a protective barrier, absorbing some of these pigments and preventing them from penetrating the nail plate.

Additionally, base coats can enhance the adherence of the polish to the nail, leading to a more durable manicure. While other options may present benefits, such as the potential for a glossy finish or an improved appearance of the top coat, the central importance of preventing staining is crucial for maintaining the health and appearance of natural nails.