It usually takes a beginner at least six months before they can make a simple picture.

"The colors in bark are like human fingerprints, and no two pieces are the same. The distinctions grow as the bark oxidizes, a process that varies with the time it takes to make a piece," Li explains.

Born into a forestry worker's family, Li developed a connection with bark art as a child. Surrounded by dense forest, she would go out with other residents to collect fallen bark to make everyday items like cigarette cases and containers.

She often watched women making bark pictures to decorate their homes, or to make as gifts for friends and family. "I was especially attracted to the layered texture and gradating colors of birch bark," Li recalls.

Whenever her grandmother and aunts were working on a piece, the young girl would help, working her way up to creating her own first designs, images of court ladies or cartoon characters.

After finishing a course in tailoring at a vocational school in Ulanhot, Inner Mongolia, about a four-hour drive from her home, Li began working at a clothing factory, where she earned just enough to make ends meet.