Paper
 
Paper
Paper is thin material mainly used for writing upon, printing upon or packaging. 

It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets.

Paper is a versatile material with many uses. Whilst the most common is for writing and printing upon, it is also widely used as a packaging material, in many cleaning products, and in a number of industrial and construction processes, and occasionally as a food ingredient, particularly in Asian cultures.

The word paper derives from the Greek term for the ancient Egyptian writing material called papyrus, which was formed from beaten strips of papyrus plants. The immediate predecessor to modern paper is believed to have originated in China in approximately the 2nd century CE, although there is some evidence for it being used before this date. 

Papermaking is considered to be one of the Four Great Inventions of Ancient China, since the first papermaking process was developed in China during the early 2nd century CE by the Han court eunuch Cai Lun. China used paper as an effective and cheap alternative to silk, letting them sell more silk, leading to a Golden Age. The use of paper spread from China through the Islamic world, and entered production in Europe in the early 12th century. Mechanized production of paper in the early 19th century caused significant cultural changes worldwide, allowing for relatively cheap exchange of information in the form of letters, newspapers and books for the first time.