Tung oil, also known as China wood oil, is a drying oil obtained from the seeds of the tung tree (Vernicia fordii or Vernicia montana). The tung tree is native to East Asia, particularly China and surrounding regions. Tung oil has been used for centuries as a finish for woodwork and as a traditional varnish in East Asian countries.

Tung oil is valued for its ability to dry into a hard, waterproof, and glossy finish. It penetrates deeply into wood, enhancing its natural grain and color while providing protection against moisture, scratches, and other damage. Tung oil is often used as a finish for furniture, wooden surfaces, and outdoor projects due to its durability and resistance to water and mildew.

In addition to its use as a wood finish, tung oil can also be found in various applications such as in the production of paints, coatings, sealants, and even in some traditional Chinese medicine practices. It's important to note that tung oil should be used with caution as it can cause allergic reactions in some individuals, and proper ventilation is necessary during application due to its strong odor and potential for combustion.