Rubber is a material, which can stretch and shrink. It is a polymer. It can be produced from natural sources (e.g. natural rubber) or can be synthesised on an industrial scale. Many things are made from rubber, like gloves, tires, plugs, and masks. A few things can be made only from rubber. Sometimes the word means only natural rubber ("latex rubber"). Natural rubber is made from the white sap of some trees such as the "Hevea brasiliensis" (Euphorbiaceae). Other elastomers, called synthetic rubbers, are made by chemical processe