Lip liner has always been the unsung hero of our makeup bags. It often gets ignored while its cousin, lipstick, gets all of the attention. But there’s a lot more to

liner than meets the eye—er, lips. You can use it to define your pout, prevent lipstick from bleeding, and make thin lips look fuller. In fact, Marilyn Monroe’s makeup artist, Allan "Whitey" Snyder, used a darker liner on the edges of her lips to create her signature contoured look. 

Ever since I was a Nancy-from–The Craft wannabe teen lining my lips with black eyeliner and filling them in with red lipstick (hey, it was a look), I was aware of the power that lip liner could wield. While my lips are naturally pretty full, I always prefer to use a liner to define my Cupid’s bow and create dimension. “If you have full lips, lip liner can be your best friend because it can define your lip shape and give you some extra lip insurance underneath your lipstick or lip gloss,” says Stephanie Valentine, aka Glamzilla, the Toronto-based makeup artist and beauty influencer. While she lauds lip liner for its versatility, she does point out that certain formulas are better. “Gel formulas will glide better on the lips, while a traditional lip liner is better for shaping and defining,” she says.  

I kept Valentine’s tips in mind when I was looking for the best drugstore lip liners to add to my arsenal. Thankfully, there are a lot of good options out there, but the one that got me immediately hooked was Covergirl Exhibitionist Lip Liner in Cherry Red ($6).