This combo photo shows inside painting works displayed at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.

Inside painting, or inner painting, is a traditional Chinese art form. It originally involved tiny snuff bottles which had pictures and calligraphy painted on their inside surfaces.

A inside painting is produced by manipulating a specialized brush through the neck of a bottle. The painting process, which is totally reversed inside the bottle, requires absolute precision from the artist.

Sun Hongyan, a 49-year-old interior of inside painting, has integrated Yunnan's natural scenery, ethnic customs, among others, into her works, thus creating the unique Yunnan school of this art.

While adhering to traditional techniques, the inside painting has gained popularity among the young with innovations. "We are elevating the inside painting to a higher level, infusing this ancient craft with a new brilliance from the modern era," Sun said. (Xinhua/Hu Chao)

Sun Hongyan creates an inside painting work at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Hu Chao)

Sun Hongyan creates an inside painting work at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Chen Xinbo)

Sun Hongyan creates an inside painting work at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Hu Chao)

Sun Hongyan creates an inside painting work at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Hu Chao)

Sun Hongyan (L) explains inside painting technique to an apprentice at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Hu Chao)

This photo shows inside painting works displayed at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Chen Xinbo)

Sun Hongyan (C) explains inside painting technique to apprentices at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Chen Xinbo)

Sun Hongyan creates an inside painting work at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Hu Chao)

Sun Hongyan creates an inside painting work at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Hu Chao)

Sun Hongyan arranges inside painting works for display at an art academy in Kunming, southwest China's Yunnan Province, July 3, 2024.(Xinhua/Hu Chao)