Natural rubber is mainly collected and processed from rubber tree.  Hevea rubber tree of Brazil is the main source.  To harvest, use knife to cut bark and collect its liquids.  After an accumulation, it will be treated with filtering and extraction preliminary processes.  This is the material to produce rubber liquid and then there are processes of filtering, bubble extinguishing, crystallizing, smoking, and wind drying to make it raw rubber.  Isoprene is the main element of nature rubber having excellent resilience and elasticity with physical properties not likely for artificial rubber to replacde it.  Natural rubber is categorized by its appearance to RSS, ADS, SKIM LATEX.  Technical assortment is recently introduced to separate it as SMR, STR.