It's a race against time, as generations of cultural heritage conservators at the Dunhuang Academy make a great effort to protect the artistic charm of the Mogao Caves, UNESCO World Heritage Site.
The team (devote) to protecting the 45,000 square meters of murals (壁画) and more than 2,400 painted sculptures of the 735 caves of the site, the construction of takes about a thousand years, from the 4th century to the 14th century. The cultural relics are the product of the cultural exchanges that took place over (century) on the ancient Silk Road.
Commonly (see) "diseases" affecting the murals include cracking and flaking, as well as erosion that is caused by changes in temperature and humidity of the caves, and the deposition of salts. To restore a mural requires an all-rounder. Restorers should know painting, master the skills of a mason (石匠) and have some knowledge of chemistry and physics (be) able to recognize the problems ad their corresponding causes and deliver a solution. They must also select proper materials and tools, and conduct experiments, formally carrying out the restoration and evaluating the effect afterward.
The restoration should respect the (origin) work and aim to maintain the status quo of the murals rather than repainting them. When the restorers find some parts of murals missing fading away, they never repaint them to create a "perfect" (appear) in restoration.
