Armed with spray paint, the graffiti team known as Beijing Penzi enthusiastically sets to work, giving a derelict building in the east of the city a new lease on life.It's taken the group at least an hour of searching to find a suitable wall, but once they start painting, they are largely ignored by the passing pedestrians, cyclists and drivers. The members estimate that around 100 serious graffiti artists operate in Beijing, spending their weekends and evenings covering authorised and unauthorised areas of the city with their personal signatures and images. Graffiti is not encouraged in Beijing and most of the Beijing Penzi members prefer to remain anonymous in the media by using their tags, or graffiti name, rather than their real names.Graffiti artists the world over attempt to leave their tag on very public locations. But in China, it is a dangerous game to play, says one of the members going by the name Zak.He uses the art form to speak his mind. Beijing Penzi member Li Qiuqiu is a veteran graffiti artist whose trademark sombre blue faces and tag 0528 have become so well-known that the artist has been commissioned to create designs for the sportswear brand Nike. Graffiti competitions have started to spring up around the country and well-known international graffiti artists are arriving to judge the results.And as local galleries begin to show more graffiti-style art and the genre gains recognition, Beiijing Penzi may have to spend less time searching for derelict buildings to decorate.