The history of true paper happened in China. Like the indigenous people of Egypt, the Chinese had, virtually five thousand years ago, developed a pictographic type of writing. The Egyptians also had been using various things to scribe on, most notably pieces of bamboo and silk woven into a fine fabric and possibly the barkcloth they were making for other unconnected purposes from the Paper. Mulberry was also used.
Historical documentation tells us that in 105 years after the birth of Christ an official called Tsai Lung, created usable paper, though it appears from finds by archaeologists that it was in fact in existence in what is now the People's Republic of China for at least two centuries before him.
Way back in olden times scribing was usually on some derivative of bamboo or occasionally on lengths of silk, which were known as Ji then. Nevertheless the cost of silk and bamboo being very heavy, these two materials were not convenient. Around then Tsai Lun thought of making use of bark from trees, rags, fish nets, and hemp. In 105AD he made a report to the emperor about the process of paper manufacture and got much praise for his thoughts. Consequently, from those distant days paper has been utilized every place and is called the "paper of Marquis Tsai".
If indeed the above historical tag is deserved, will very likely not ever be known! Nonetheless the most important factor is that it was found that they could pound particular substances taken from plant material in to a pulp, purge impurities, float the pulp in water, filter it out onto textile sheets and give it time to dry out. After drying, it caked into a hard, resilient sheet that was remarkably light, and as long as it did not come into contact with water, turned out to be exceedingly robust.
This the easiest of papermaking techniques is even now practised in exactly a similar way in and around Nepal and Tibet, the first places to pick up the techniques from South East Asia. A basic frame makes use of a cloth manufactured from cotton stretched over one side, thin paste is poured into the opposite side and moved around until it has reached a level. It is then suspended so that it will let the liquid to drain out of it and the mush to dry in to a sheet of parchment which will be able to be taken off.
At some point in time a developer with great skills figured that building a frame with ribbing and putting in place a delicate bamboo mat that is removable across this, would enable the process to be quickened enormously. Rather than using a single mould for every paper sheet, severely limiting the number of sheets that may be produced at the same time, a stack of sieved grume was able to be built up layer upon layer, with only a piece of cotton thread between them to enable later separation. The stack would then be squeezed lightly, and each sheet of mash shifted to a dry place.