Cork Burn Your Name Hair Clips This listing is for THREE Same name cork hair clips Size of the hair clip: 4.9cm x 1cm / each Type: Alligator Hair Clip with Teeth Material: Made by natural cork wood. Cork wood come from bark of cork oaks. When a cork oak reaches 25 years old, a 1 inch-thick layer of cork bark is harvested without damage to the tree. The bark of mature cork oak can be harvested every nine years. After sterilization, cork bark is pressed flat into a thin cloth.