The History of Paper - American Forest and Paper Association
: To prevent ink from spreading and to add rigidity, paper can be "sized" with substances like animal glue, vegetable gums, or rosin. Writing a "Solid" Academic Paper
To create a durable, "solid" sheet of paper, you must focus on the preparation of pulp and the removal of water.
: The strength of the paper comes from interweaving these fibers. A mold is used to scoop a thin layer of the slurry, allowing water to drain through a screen.
: To ensure a smooth, high-durability surface, the wet sheets are pressed to remove excess water and then dried on boards.
Creating a "solid paper"—whether you mean a physically durable sheet or a high-quality academic document—depends on following structured methods developed over centuries. For physical paper, the focus is on fiber bonding, while for academic writing, it is on evidence and logical flow. Physical Papermaking: Ensuring Durability
: Historically, solid paper was made from rags (linen or cotton), mulberry bark, or hemp. These materials are cut, mashed into a paste, and mixed with water to create a slurry called "furnish".
If you are writing a research paper, "solidity" refers to the strength of your arguments and the quality of your sources.