cork
Cork refers to the thick skin layer between the wood crust and the trunk. There is a tree or a cork layer. Typically, it is mainly cork oak. It is light and resilient, and it is used for bottle cap, insulation, buoy, fishing rod material, rinolinium, waterproof material, air bag of apparatus, gun stopper of pistol, etc., and also makes black paint by burning cork scrap. Corks used in bottle caps, insulators, buoys, fishing tackles, memo boards, and fillers are mainly made from cork oak.