Balloons these days are made up of the artificial rubber or the latex. Earlier the natural material was used for the production. However these days the chemicals used for the latex are made up from the wasted latex from other processes. This way the recycling of the chemicals helps creating a new product. Prior to the natural rubber, the pork fat was used for the baloons in the old rome and other places.
Today most of the production happens at the chemical factories. The wasted chemicals are often used for the latex. And the type of the rubber generated is processed through number of tests and then the smallest possible form. This form is then used for creating the balloon. Colors are added during final form of the rubber or the latex. Such balloons again go through the quality control process. And finally after checking the quality of the rubber, they are cut in the size respectively. Lot of such designed balloons often end up wasted so again final process requires quality control. Different design and the process being done at the small level so for each manufacturer the process may differ.