The history of proper paper started in South East Asia. Similar to the people of Egypt, the Chinese had, nearly 50 centuries in the past, brought out a type of writing that used pictures. The Egyptians too had been using many different objects to scribe upon, usually strips of bamboo and processed silk and it is possible that the barkcloth they were making for other purposes derived out of the Paper. Mulberry was made use of too.
Historical documentation leads us to believe that in 105AD a member of the government by the name of Tsai Lung, invented usable paper, though it is almost certain from finds by archaeologists that it was actually being used in China for probably two centuries before him.
Way back in ancient times scribing was generally on bamboo or occasionally on pieces of silk, which were then called ji. Nevertheless the prohibitive cost of silk and bamboo being too weighty, these two materials were not of great use. About this time Tsai Lun thought of making use of the bark from trees, hemp, fish nets, and rags. In 105 years after the birth of Christ he made a report to the emperor on the process of paper manufacture and got high accolade for his ideas. Consequently, from those days paper has been in use all over and is called the "paper of Marquis Tsai".
Whether the above historical tag is correct, will very likely never be known! But the main factor must be that it was discovered that they could grind particular substances taken from plant matter in to a mush, eliminate impure materials, float the mush in liquid, screen it onto cloth sheets and give it time to dry out. After drying, it dried into a hard, resilient sheet that was extremely light, and provided that it did not get wet, proved remarkably robust.
This easiest of paper making techniques is still in use in precisely a similar way in and around Nepal and Tibet, the very first places to learn the technolgies from what is now the People's Republic of China. A simple frame has a type of cotton cloth stretched over one side, thin mache is emptied into the opposite end and spread around until it is even. It is then left hanging in order for it to allow the water to drain and the mash to dry in to a parchment sheet which can be removed.
There came a time when a clever developer worked out that building a frame with ribs and placing a fine bamboo mat that is replaceable over it, would enable the procedure to be accelerated fantastically. Instead of tying up one mould for each sheet of paper, therefore severely restricting the number of sheets that can be produced at one time, a stack of sieved grume was able to be built up layer upon layer, with merely a length of cotton thread between them which would help with separation at a later time. The stack would then be squeezed very slightly, and every layer of paste transferred to a dry place.