Sheet masks are thin, face-shaped sheets made from materials like cotton or hydrogel, soaked in a serum rich in beneficial ingredients. They are designed to adhere to the skin, allowing the serum to penetrate deeply and provide hydration, nourishment, and other skin benefits. Typically used for about 15 to 30 minutes, sheet masks are popular in skincare routines for their convenience and instant results. They come in various formulations targeting specific skin concerns, such as dryness, dullness, or acne, making them a versatile option for many users.