Think of these products like the primer you'd use for painting a house. The goal is the same: to fill in any bumps, lumps, and uneven spots so that whatever you put on next starts on a smooth, even surface. In the case of your face, that would be concealer, foundation, or powder.
Many women find primers to be especially useful around the eyes, where fine lines can become more prominent when makeup settles into the crevices, as well as in areas with enlarged pores. When you use a primer on areas that tend to be oily, like the eyelid, makeup tends to adhere better and last longer. Also, a thin layer of primer all over can help makeup stay put.
Another primer perk: Whether your skin is oily or dry, acne-prone or sensitive, you can use a primer, since the moisture it imparts comes via silicone, not oil.
How to Use Makeup Primers
Apply these products sparingly. Less definitely is more. After you apply sunscreen and a moisturizer, then comes the primer. Use your finger to apply only the thinnest dabs around your trouble spots. This way, you create a very fine film, but you can blend it out as far as you like.
Finally, because primers have staying power, be diligent about washing your face well each night. Consider an electronic cleansing brush, which gently but effectively gets your face squeaky clean. But any cleanser and water will work, too.
Find more articles, browse back issues, and read the current issue of "WebMD Magazine."