According to the Portuguese cork association, cork is a material that has been with humans since ancient times. In early days, it was mainly used in architecture, especially in Mediterranean countries where it originated. Now, due to the development of new materials based on the cork, the continuous improvement of the cork features, as well as importance of natural and sustainable materials, the use of cork in floors, walls, and insulation is being promoted around the world.

If strictly speaking, cork is not actually wood, but the bark of oak. Due to the cork fibers, basis of the cork, there are about 40 million cells per cubic centimeter, which are filled with air between cells and inside cells. When the pressure is outside, the cells and their gaps shrink, and the air pressure inside and between the cells makes them to return to their original state when they lose external pressure. As a result, the soft feature of the cork is shown here, and this particular inner structure makes cork have a strong toughness and restorative.

EU is the largest producer of cork, mainly in the southern Mediterranean countries, among which Portugal the most. There are also distributions in Qinling mountains district of Shanxi province. Currently, the world annual output of cork are 350,000 tons, Portugal accounts for more than 50%, Chinese annual output are 50,000 tons, Qinba area of Shanxi and neighboring provinces account for more than 65%, and more concentrated.