Sheet masks are pretty self-explanatory. Open the package, place the serum-soaked sheet on your face, snap a few selfies, remove the sheet and bask in the surge of hydration. But we betcha didn’t know that those little gauzy guys are actually the windows into determining your exact skin type.
Here’s what you do: Apply any moisturizing sheet mask as you normally would. But instead of peeling it off after ten to 20 minutes, leave it on for a solid 40. When you do remove the mask, you’ll want to scan your face. The areas that absorbed all the hydration and could use even more—those are your dry patches. The spots that feel greasy or over-moisturized are—you guessed it—the oily areas. And any parts of your face that feel refreshed and supple are “normal” skin.
You might have only one or two of these signs if your skin skews dry or oily all over. And, sure, that’s probably already obvious to you. But if you have combination skin, you’ll really be able to confirm which parts of your face need the most love. Bonus: You don’t even need to pay a derm the big bucks to tell you.
In fact, we just found another excuse to raid the sheet-mask aisle.