A Korean sleeping mask is a leave-on mask applied as the last step at night and left on until morning. This collection includes Laneige, with its Lip Sleeping Mask, the SKIN1004 Madagascar Centella Hyalu-Cica Sleeping Pack, The History of Whoo Gongjinhyang Vital Hydrating Overnight Mask and P.CALM overnight masks. Use a thin layer of a face mask after serum and cream, and read the role of sheet masks in Korean skincare for more mask tips.