What is the primary purpose of using a toner in skin care?

The primary purpose of using a toner in skin care is to balance the skin's pH after cleansing. When a cleanser is used, it can disrupt the natural acidity of the skin, making it more alkaline. A toner helps to restore the skin to its optimal pH level, typically around 4.5 to 5.5, which is essential for maintaining a healthy skin barrier. This balanced state can enhance the skin's ability to absorb subsequent products and treatments effectively.

While toners may have additional benefits, such as removing traces of impurities or providing hydration, their main role revolves around pH balance. This is crucial for skin health, as maintaining the right pH can prevent issues like dryness, irritation, and increased susceptibility to blemishes. Thus, the focus on balancing the skin's pH makes this the correct answer.