What is the proper method to mix nail polish in the bottle?

Rolling the bottle is the preferred method for mixing nail polish because it gently combines the pigments and solvents without creating air bubbles. This rolling motion ensures an even distribution of color and components, resulting in a smooth application when using the polish.

Shaking the bottle vigorously can cause air bubbles to form, which may lead to a less smooth application and affect the polish's texture and finish. Stirring with a brush is not ideal as it can introduce further air and may not adequately mix all components. Using an electric mixer is impractical for nail polish, as it is unnecessary and could potentially damage the formula. Therefore, rolling the bottle strikes the right balance of effective mixing while preserving the integrity of the polish.