Rubber planters in East Sumatra adopted highly scientific methods in growing and harvesting rubber trees. The planters were systematic in numbering each tree and recording its pedigree. To ensure the quality of each crop, they gathered and planted the seeds of trees that yielded a higher quantity of latex. Further, the planters established laboratories in which plant diseases were studied to to identify and eliminate potential harmful risks to the crops.The images here show how the sap was gathered and processed in the factory, where the latex was hardened and flattened into sheets. The rubber sheets were then cut down to the needed sizes. The finished product resembled a fine piece of white or cream coloured wash-leather.
