MTV "Corporations regard graffiti as a promotion tool for attracting young people, and the government uses graffiti for city beautification," says Wang of Radio Beijing.
Song has participated in a few commercial graffiti contests. Sometimes he's invited to do commercial advertising, meaning his work will last longer, and, perhaps more importantly, he gets paid.
"I used to hate commercial graffiti," he says. "I used to think graffiti should be free and once you take their money, you have to paint what they want.
"But now I understand how it helps others to know about graffiti and makes graffiti more acceptable. Plus they usually provide me with free painting materials which I can barely afford."
Corporations pay 300-400 yuan a square meter of graffiti, but have the right to decide the content, he explains.
"To be honest, I don't like it. I want my work to be kept a long time, not used as an advertisement."
Song first saw graffiti on MTV. In second grade of high school, he sneaked out of his home at midnight and sprayed his first graffito on the wall of a small square nearby. Four meters high and five meters wide, he combined two blue letters – S and W – an abbreviation of his name.
Graffiti is a criminal activity in most countries and China is no exception. Most of his friends who paint outside have been caught by police at least three or four times and fined hundreds of yuan.
Song hasn't been caught yet.
"I am lucky," he tells the Global Times.
Song spent a semester painting a 100-meter wall. His graffiti included themes of college life and commemorating the dead of the Sichuan earthquake. Environmental protection workers whitewashed over his work the same day it was completed.
"It was really frustrating," Song says. "Graffiti in Western countries might hail from black gangs' street signals, but in China it's just art."
All the pictures were carefully designed and painted, he says: totally different from "street bombing," the almost-unintelligible scribbles that involve stylized renderings of assumed names sprayed on trains, buses or security gates.

Song Wei works on Zuo Zi Ji in Hubei. Photo: courtesy of Song WeiGallery China's largest city has a 1.25-kilometer stretch of graffiti, sponsored by the Chongqing municipal government.
"They hired some painters to paint the whole building on that street. The graffiti is large in scale, but really ugly." Zhang said in an interview with Southern Weekend.
The first time he painted his trademark profile of a bald man in 1995 was at the Deshengmen flyover in central Beijing.
He signed off on it as "AK-47," the legendary Soviet assault rifle. Pretty soon his baldies were appearing all over the capital city and the media began speculating on the identity of "China's first graffiti artist."
Zhang never forgets the time he passed one of his signature portraits and saw something written underneath:
"What the hell are you doing? Who are you?"
He took photos of the response and named the photo "Dialogue."
"I was very excited," he said. "Someone had responded to my expression."
The Zhang of today doesn't sneak around the mean streets late at night to spray walls. He is a professional artist who sells his work at a gallery. One photo he took of his graffiti sold for more than $50,000.
"Zhang cleaned up," Liu Yuansheng, a photographer who spent years documenting Chinese graffiti, wrote in his blog. "He became rich and his life was changed, so he abandoned graffiti."
Source: The Global Times【1】 【2】