In the Asia Art Center in 798 Art District in Beijing, artist Chen Yan's works stun visitors with her creation of painting on film bromide. [Photo provided to China Daily]

Chen still remembers how fascinating it was seeing the images slowly revealing themselves.

She's also inspired by the perspective of medical X-ray films.

"I'm intrigued by the feeling of seeing through what cannot be seen directly," says Chen.

Chen started painting on exposed X-ray films in 2014.

She claims that painting on these films creates a sense of strangeness and alienation, which allows her to break through from the inertial pattern of oil painting and feel the irreplaceable charm of the material.

Chen considers the film as a relatively uncontrollable medium, as each touch will leave an irreversible trace. And the "brush" she uses, which is a knife or sometimes a stone, strengthens the difficulty of the challenge, as they can easily tear the film.