Toners were originally designed to finish the cleansing process – they removed soap scum, restored the skin to its proper pH, and tightened pores to provide a smoother canvas for makeup application. Cleansers, for the most part, have improved to the point where toners are usually no longer needed for those purposes.
Many manufacturers have become aware of this fact and are now designing toners that provide benefits above and beyond their original cleansing purpose. There are clarifying toners that help decongest pores and control oil, hydrating toners that provide an extra layer of hydration under moisturizer and that can also be spritzed on, over makeup, for periodic pick-me-ups (great for long plane flights), there are brightening and skin lightening toners that exfoliate and even out skin tone, was well as anti-inflammatory toners that help reduce redness and soothe irritated skin.
These kinds of toners are useful for those who either prefer very simple routines, without heavy creams or moisturizers – they just cleanse, tone and put a sunscreen on, or they are useful for people with complicated routines that use several different treatments. Toners absorb quickly into the skin and do not leave a film or emollient layer that can inhibit the penetration of actives that are applied afterward – an important quality for those who need to use multiple types of actives in their routine and cannot find them all in one product.