four greatest inventions of ancient China—printing

In China, the earliest books are made with a handwritten. Copy books are time-consuming and laborious, and prone to making mistake.

In the 4th century, Chinese learned to make rubbings on stone tablets or bronze vessels, and this way is considered the most original printing method.

In the Sui and Tang dynasties, people invented the block printing.The wood block is carefully prepared as a relief matrix, words are carved on board in reverse, and bulged out. After coated the words with ink, and put a paper upon it, a page is done with a gently brush. At that time a skilled craftsman can print 2000 pages per day. However, although block printing can print a lot, the engraving is useless when a page of a book is finished for the characters on the wood block are fixed.

During Northern Song Dynasty, Bi Sheng invented movable-type printing after years of experimenting .He carved words on square clay pieces which are made of daub, burned hard, then movable-types are finished. When you’ll start a print, put the movable-types in order in a piece of iron plate which is with frames, roll the words out, fix and chart ink, then printing can start. The types can be reused after printing, so this printing method is fast and energy saving, and movable types can be correct when a mistake is discovered. So, the invention of movable-type printing is a great beginning to the world printing history.  

After that，the printing was steadily improved, people use wood moveable，bronze moveable and lead moveable to print, and the quality of printing became higher and higher.

在中国，最早的书籍是用手抄成的。抄书又费时又费力，而且容易出错。

公元4世纪，中国人掌握了用纸在石碑上拓印的方法，得到了黑底白字的拓本。拓印可以称作最原始的印刷方法。

到了隋唐时期，人们又发明了雕版印刷，就是把字反刻在木板上，让字凸出，涂上墨，然后把纸铺在上面，轻轻一刷，一页书就印好了。那时候一个熟练的工匠，一天能印两千张。不过，雕版印刷虽然可以大量印书，但是由于雕版上的文字是固定的，所以一页书印完以后，这块雕版就没用了。

到了公元11世纪，宋代人毕升发明了活字印刷术。毕升用胶泥做成一个个方形的泥块，在上面刻上反字，用火烧硬，这就成了活字。印书时，把活字按顺序排在一块有框的铁板上，压平，固定，图上墨，就可以印刷了。印完后，把活字拿下来，下次可以再使用。这种印刷方法又省力又迅速，发现错误，还可以改正。毕升发明活字印刷术是世界印刷史上的伟大创举。

后来人们又用木活字、铜活字、铅活字印书，书籍的印刷质量越来越高了。