Raw, natural latex is a white or yellowish cloudy liquid, which looks a bit like milk. Latex is made by some plants, in particular the Hevea tree originally found in Brazil. The most important sources of natural rubber today are plantations in Malaysia and Africa.

Producers of rubber must harvest the raw latex from the trees, by scoring the trees with shallow cuts and letting the sap ooze from the cuts into buckets. The latex is collected in large containers, filtered, and mixed with alkali to prevent the fluid thickening. It is then shipped in liquid form to different parts of the world to be processed.

Latex must be mixed with additives to make it the right thickness and slow the rate of decomposition before it can be used to make balloons. To give it color, pigments like metal powders or organic dyes are mixed into the latex.

Preparing the latex

· The latex will be poured into tanks into which balloon shaped forms will be dipped. The tanks are kept at a certain temperature and may include stirring mechanisms to keep the latex circulating to avoid settling.

Dipping the forms

· The balloon forms are first heated, then dipped in a tank of solution which makes the latex thicken for a few seconds. When the forms are dipped in the liquid latex, the solution will cause the rubber to gel in a thin sheet around the balloon forms.

Making the ring

· A lip is formed on the neck of the balloon by rolling the edges of the rubber using brushes or rollers. This creates the ring around the opening of the balloon.

Removing excess solution

· Next, the forms are immersed in a tank of leaching fluid (often plain water) to dissolve and leach away excess solution from the rubber.

Curing the rubber

· The rubber on the balloon forms must be dried and cured. This can be done by putting the rubber-coated balloon forms into an oven.

Removing the balloons

· The balloons are then removed from their forms. This can be done by blowing them off using a spray of water or air and collecting the balloons in a basket or net.
· If the balloons are removed using a spray of water, they are then dried in large tumble dryers.