They work from 8 am to 5 pm, and get paid 330 yuan a day.

Ni was first assigned to paint the handrails of the open-air stairs around the commercial building in the center of the venue, which looks like a four-leaf clover.

Later, he worked in the hall for the country exhibition.

Not all of the handrails need repainting. He looked for rusty parts, fixed them with polyester putty and then covered them with paint.

The painting was finished by and large on Oct 23, and most of the workers were dismissed.

Ni and five other painters were asked to stay on standby in case something needs a final touch.

All of the painters are from Qidong, a city on the northern bank of the Yangtze River. It's a two hour drive to to Shanghai.

"It's such a grand occasion, and I feel honored to be part of it," Ni said.