The video below is a time lapse capture during the build of The VERY Tall Tale of Jack and the Beanstalk, an Airigami project I was involved in contructing in 2014.
50 000 balloons, 4 days, 75 artists, 5 floors high
This video is about how balloons are made, from raw latex to the finished balloon.
These particular balloons are made by Qualatex and are the brand of balloon that I use. Obviously I use more shapes than the round ones shown in the video.