The 6,000 years of human civilization history can be divided into three eras, each with its own obvious technical symbol.

Egyptian civilization was the peak of the first era, with the invention of iron, which caused a phasing-out of expensivebronzeproductions, as the symbol.

During that time, agricultural productivity was greatly promoted by the great use of iron. At the same time, iron weapons also played important roles in the military domain, which greatly improved soldiers' ability in attacking and defending.

The technical symbol and propelling force in the second and third eras was papermaking andprinting, both which originated in China.

Paper was invented in China's Han Dynasty(206BC-220AD). Before then, China's 2,000-years civilization could not compare with Mesopotamian civilization in West Asia and the ancient Egyptian civilization along the Nile in North Africa. However, after the invention of paper, China rapidly became the center of civilization as well as the main contributor of culture and technology to the world.

The appearance of Jiagu Wen (oracular inscriptions on tortoise shells and bones) ended the history of people keeping records by tying knots. This was the first time people could record history and thought by writing. However, because of the limitation of tools, such initial records could not last.

Papermaking changed human history. Even earlier than Cai Lun's (a eunuch inHan Dynasty, who is conventionally regarded as the inventor of paper) time, paper's prototype had appeared in China. The appearance of paper created a huge cultural influence, and enabled a big cultural development during the Wei (220-265) and Jin (265-420) dynasties.

Since then, intellectuals began to pursue a spiritual culture: they started to appraise moral quality and the tests of artistic interest, while intensively yearning for cultural creation.

The invention and dissemination of papermaking promoted the passing on of culture from one generation to another and the exchanges of thoughts and ideas, hence impelling the civilized development.

Printing's arrival brought a new power to the civilized development. It broke the authority's cultural monopoly, as more and more common people could read books.

China is not the only country that profited from printing and papermaking. After several years, those technologies spread and became prevalent in Europe. The Renaissance (14th-16th century) and the Reformation (16th century) came about with the two inventions' catalysis. Printing and papermaking liberated the culture from the church and the aristocrats' control, and provided a venue for the dissemination of new thought as well as new works.

Scientist Francis Bacon once gave a high opinion, when he appraised China's four big inventions' (including papermaking and printing) contribution to the world, saying, "They completely changed the world's appearance…there was no other country, religion, or person who had displayed as big an influence on human progress than them."

The Development in Papermaking   1 Bamboo segments were cut and soaked in ponds to loosen the tough outer layer. 2 The pulp was then produced using ground and boiled bamboo, hemp and cloth rag. 3 A thin layer of the mixed pulp was lifted and strained from a vat using a finely screen 4 The resulting sheet was pressed to release lingering moisture forming sheets ofpaper. 5 They are mounted to be smoothened out 6 They are then applied to the sides of a wood-fired heated wall for final drying. The variety of material played an important role in papermaking development. Hemp and bark were the main material for making paper inHan Dynasty, while during the Wei and Jin dynasties (220-420), mulberry bark paper and cane paper were invented. With the development of society and culture, paper was widely used and the technique of papermaking continued to improve. Bamboo was used to make paper later in theTang Dynasty(618-907) as it grew rapidly in large quantities, and its long fiber, fine and strong, made it excellent papermaking material. However, the technique required to make bamboo paper was complicated. Therefore, people continued to look for other materials, experimenting with a mixture of different proportions of many kinds of plant fiber to produce different kinds of paper. Zhi Yao (paper medicine) was an important invention in papermaking. In papermaking, laborers often put some plants mucilage (solution of gum, glue, and so on) in the paper pulp. In ancient times, the mucilage was called Zhi Yao. Zhi Yao was used as a deflocculant (an agent which can prevent certain materials from sticking together), which can prevent the viscidity (sticking together) of textile fiber. Ancient Chinese people commonly squeezed out mucilage from the yellow hollyhock, carambola cane, rose of Sharon, and so on. The Invention of Printing Technology---A Need for Cultural Spread   From theQin dynasty(221-206BC),Chinese charactersdeveloped rapidly. A book titled Shuowen Jiezi that was written in the EasternHan Dynasty(25-220)contained 9,353 characters; and a book titled Yu Pian that was written in theNorthern and Southern Dynasties(386-589) contained more than 22,000 characters. With the development of Confucianism, Taoism, and various other scholars' thoughts, more and more works appeared. China's population grew rapidly; at the end of theWestern Han Dynasty(206BC-24AD), the population had reached nearly 60 million, spurring a great demand by people for books to read. Therefore, a need for new technology (for making books) became urgent. Thepaper's invention provided a kind of high- quality and cheap writing material for the society, which promoted the books' development to a certain degree. But the method of writing books by hands was not suitable for large books, thereby leading to a gap in cultural dissemination. Under those situations, Chinese people invented theprintingtechnology, offering humanity's development a generous gift in the process.