A ballpoint pen painting depicts the Great Wall by Liu Kai. [Photo provided to chinadaily.com.cn]

In 2015, a group of his blue-and-white drawings attracted online attention and won netizens' praise for being "as beautiful as the famous blue-and-white Qinghua porcelain".

Before he becomes an artist, he was a high-school student and then a migrant worker. His ability to draw was not taught by school but himself.

When he was a senior high school student in 2007, he developed an interest in drawing and picked up the ballpoint pen. Since then, he has not stopped practicing even when he went out to work.