Compass , paper making , gunpowder and printing were great technological achievements that the Chinese nation dedicated to the world , which altered the historical course of the human beings . They reflected and represented the brilliance and prosperity of the ancient Chinese civilization . 

Paper making marked a preeminent invention of the ancient Chinese working people . Prior to its invention , the Egyptians wrote on thin barks of stalks of papyri , the Europeans wrote on sheep skin , and the Chinese resorted to tortoise shells , bamboo , wood and silk cloth . In the Western Han Dynasty , people processed silk fiber into thin pieces , called silk fiber paper , which was rudimentary paper making . Because silk was costly , people processed ramie fiber into thin pieces that was the plant fiber paper . In the Eastern Han Dynasty (beginning of second century A.D.) , Cai Lun assimilated the previous experiences and carried out many experiments .
　　Eventually he invented a new kind of plant fiber paper , making full use of scrap materials including bark , ramie combings , worn cloth , fishing nets , etc . Thus , the source of raw materials was enlarged and the cost was reduced . His new technique spread quickly , and he was recognized by the later generations the inventor of paper . By the Jin Dynasty , paper was widely used , taking the place of bamboo slips and silk cloth . During the sixth century A. D. the Chinese paper making technique spread to Korea , Vietnam and Japan . In 1150 A.D. the first European paper factory was established in Spain , lagging behind Cai Lun’s invention by over one thousand years .

　　“No matter how highly the effect of the invention of paper making upon the whole course of later Western inventions is evaluated , the evaluation is never an overestimation.” (Decker Durdon : “The History of the westward Spread of Chinese Articles.”) In the medieval Europe , parchment was still the main carrier of information . It is estimated that to produce a Bible needed at least more than 300 sheets of sheep skin . Cultural information spread very slowly due to the scarcity of carrier material . The production of paper provided a most advantageous condition for the flourish of education , politics , commerce , etc . , in Europe at that time . In this sense “The world has been more benefited by Lord Cai Lun than by other more well-known celebrities”. (ibid)