From Thingpedia

Natural rubber

Natural rubber comes from trees. Rubber trees grow best in hot, humid regions with soil rich in iron and alumunium.To make rubber, holes are cut into the bark of the tree, which allows fluid to flow out. This fluid is called latex. Cups are hung under the holes to collect the latex as it drips out. This is called “tapping”. [1] For the collected latex to become rubber it must be processed in large tanks or air-tight containers.

Synthetic rubber

Synthetic rubber is derived chemically by mixing multiple petroleum based molecules.[2]

What is rubber used for?

Rubber is used to make erasers for pencils.