Norbu Sida sketches carefully in the workroom where he has worked for five years. [CnDG by Jiao Meng]

"It has taken me five years to imitate the 40㎡ frescos near the mandala in Potala Palace, and I haven't finished yet," said Tibetan thangka painter Norbu Sida.

Norbu was interviewed by China Development Gateway (CnDG) in Potala Palace while working on the mandala in the red palace on August 9.

With more than 30 years of drawing experience, he was selected as the official thangka artist by the Tibet Autonomous Region (TAR) in 2008.

"I spend every Monday, Wednesday and Friday the past five years in imitating frescos near mandala, and it's free of charge. I believe it's a holy mission to protect artworks in Potala Palace," he said.

According to him, the frescos near the mandala were painted during 7th Dalai Lama (1708—1757); however, the frescos have been damaged and many parts of them are unrecoverable.

"My job is to imitate the frescos and sketch them in line drawings with 1:1 proportion. If some part was damaged, I would leave it blank," he explained.

"It needs full concentration and patient to paint line drawings exactly the same as it in frescos. It takes me months to finish one painting," he added.

"If the characters were lost, I would use an 'x' to replace them on the painting, and check scriptures to find the original sentences," he said.

"I believe it's the best way to protect frescos with damages, so the copies will become precious documents to study and recover the frescos in the future," he explained.