It took seconds to release the 100,000 balloons for the grand gathering in honor of the centenary of the founding of the Communist Party of China at Tian'anmen Square in Beijing on July 1, but He Jiangbin and his teammates had been preparing for 120 days.

The balloon team had just 90 minutes to inflate the balloons on the morning of the gathering, and every one had to be the same size, so more than 400 volunteers practiced for months to ensure there were no errors.

He, who is chairman of the China Balloon Art Association and was a key member of the event's technical instruction team, said volunteers worked in pairs to inflate and tie the balloons.

"At first, it was hard for them to finish one balloon in 10 seconds. But after months of practice, and hundreds of balloons a day, pairs were able to make at least two balloons in 10 seconds regardless of weather conditions, rain or scorching sun," he said.

He is based in Shanghai but received a call from Beijing to work as a technical instructor for the balloon release in March. Over the past months, he has traveled dozens of times between the two cities to discuss plans for the release with his 30 teammates, how best to train the volunteers and to devise emergency solutions.

At a training site in Beijing, He and his colleagues instructed volunteers on every little step. In each pair, one volunteer was responsible for inflating the balloons and ensuring an equal size, and the other was responsible for tying them.

Balloons had to be exactly 25 centimeters in diameter.

A box with a hole that size cut out of it was given to each pair to ensure their balloons were inflated properly.

"Only when such a large number of balloons are of the same size will they rise at almost the same speed and create the effect of a gigantic, colorful balloon curtain," He explained.

According to the schedule, the balloons had to be ready and at a designated spot on the square at 7 am on the day of the release, which meant that they would be stored for around six hours from the moment the first balloon was inflated.

He's idea was to put the balloons in 100 boxes covered in two layers of different material to protect against sun and rain.

"To ensure complete safety, helium was used for inflation and the balloons were made from natural latex that was 100 percent degradable."

"Even if a balloon got sucked into a plane engine, it would disintegrate instantly, just like a small piece of paper," he said.

Separately in Shanghai, hundreds of representatives from government and industry, Party historians, lighting and art professionals and musicians worked behind the scene on the Forever Following the Party light show that was projected across skyscrapers and historical buildings on either side of the Huangpu River between June 30 and July 4.

Yuan Qiao and his team provided technological support to make the show possible.

Speaking about the logo for the CPC centenary in the heart of Lujiazui in Pudong district, which played a key role in the show, the associate professor at the Environmental Science and Engineering Department of Fudan University said that the five laser beams pointed at the logo were able to achieve an illumination level of 160,000 lumens, the brightest such light in the world.

"In terms of the entire six-minute light show that was staged repeatedly each night, my team worked on the lighting design, special effects, animation and video creation," he said.

"Actually, we collaborated with multiple departments at Fudan to solve technical problems and so were able to tell the story of the glorious city where the first CPC National Congress was held."