Lip liner is a cosmetic product used to outline and define the lips before applying lipstick or gloss. It serves several purposes, such as preventing lipstick from feathering, enhancing the shape of the lips, and improving the longevity of lip color. According to different types of Lip Liner, it has pencil Lip Liner,retractable or Twist-Up Lip Liner,Liquid Lip Liner,Gel Lip Liner: