The origins of true paper started in China. Like the Egyptians, the Chinese had, virtually 5,000 years in the past, brought out a pictographic form of writing. The Egyptians too had been making use of various objects to write upon, most usually strips of bamboo and silk woven into a fine fabric and possibly the barkcloth they used for other unconnected purposes derived out of the Paper. Mulberry was made use of too.
History points to the fact that in 105 years after the birth of Christ an official named Tsai Lung, developed paper, though it is almost certain from finds by archaeologists that it was in fact being used in South East Asia for probably two centuries before Tsai Lung.
Back during times gone by setting down words was usually done on some derivative of bamboo or occasionally on pieces of silk, which were called Ji in those days. But the cost of silk and bamboo being weighty, these materials were not convenient. Due to this Tsai Lun thought of using bark from trees, hemp, rags, and fish nets. In 105AD he submitted a report to the emperor regarding the process of paper manufacture and got high praise for his ideas. Consequently, since then paper has been in use every place and is known as the "paper of Marquis Tsai".
If indeed this historical reference is correct, will probably never be uncovered! Nonetheless the most important factor is that they found that if they ground certain substances derived from plant material into a mush, evacuate impure substances, float the mush in liquid, sieve it onto cloth sheets allowing it to dry. When it dried, it conglomerated into a hard, durable sheet that was remarkably light, and providing it did not get wet, turned out to be incredibly resilient.
It's a fact that this very easy of papermaking techniques is even now in use in exactly the same way in and around Nepal and Tibet, the first regions to make use of the craft from what is now the People's Republic of China. A simple frame utilizes a type of cotton cloth pulled and held over one side, very watery pulp is poured in to the opposite side and spread around until it is smooth. It is then left so that it will let the water to drain and the paste to dry in to a parchment sheet which may be removed by stripping off.
At some point in time an extremely talented developer figured that making a frame with ribbing and putting a fine replaceable bamboo mat over it, would enable the process to be quickened enormously. Instead of utilizing a single mould for each paper sheet, severely limiting the amount of sheets that can be made at one time, a stack of sieved mache could be built up a layer at a time, with just a strip of cotton thread between them which would help with later separation. The stack would then be squeezed very gently, and every layer of grume shifted to a dry place.