WARNING: The following contains spoilers for Season 2, Episode 5, "Steam Gorilla" of Dr. Stone, now streaming on Crunchyroll.
Whether in a proper isekai or a post-apocalyptic world, the fact remains that modern conveniences that were once taken for granted suddenly become the height of luxury -- and perhaps none more so than paper. While Main of Ascendance of a Bookworm desires the flat sheets to replicate their primary purpose as a surface to write on, Senku of Dr. Stone has a little more unorthodox usage in mind -- creating tank plating by sandwiching it around layers of unhardened plastic.
Aside from striving towards different uses of paper, Senku and Main also differ in how they set out to obtain it. And Senku's is certainly more expedient.
While most Ascendance's first arc is spent finding a way for Main to record her thoughts more permanently, Senku sets out on the task in Season 2, Episode 5, "Steam Gorilla," creating workable paper in less than a minute of screen-time. Main spends two and a half episodes trying to make paper as we know it today -- though she tried various other ideas, like papyrus and clay tablets first. Still, the fact remains that it took her over a month and more than a little trial and error and help from Benno and the Gilberta Company's connections backing her too. So how did Dr. Stone, a series known for its scientific endeavors, make making paper look so easy?
Unlike Main, Senku isn't trying to make quality paper for writing on. Instead, that happens to be a bonus ability they unlock after its creation. In the wilds of 5740, parchment is easy to come by as another possible use for leftover animal skins and pelts. As a result, so long as the paper is large enough and created quickly enough to make the tank's exterior, Senku doesn't care how it looks. For that reason, rather than search out soft, young wood to create the best possible product as Main does, Senku instructs the villagers to grab as many weeds as they can, noting that it doesn't matter what kind of plant it is.
Another significant difference is the process they each use. Main may already be in a pre-established society, but she has little access to the necessary materials and has had to rely on arduous and straightforward methods. The process she uses involves steaming the wood, peeling off the bark, boiling it, beating it, removing knots and other impurities, then straining it, drying it and more. All in all, it's easy to see how it ends up taking a few months for her to get her prototype paper ready for Benno.
In contrast, Senku's chemically-based background sees him skip most of that process, opting for some sterner stuff by boiling the plants in sodium hydroxide rather than plain water to help it break down faster. Senku's chemicals are unlikely to be known by the residents of Ehrenfest or something that Main herself is familiar with. Furthermore, despite the help and the Gilberta Company's backing, Main and Lutz still did much of the work themselves -- at the physical age of six. Senku not only had Kaseki, the miracle craftsman, on his side but almost all of Ishigami village assisting him.
However, while Senku's method is undeniably faster and easier than Main's, it still probably took much more time than the show and manga would lead viewers to believe. Though it's referred to as sodium hydroxide, Senku likely took the time to create an aqueous solution rather than using pure sodium hydroxide, which, with its 1388 degree Celsius boiling point, would have just burned the greenery. Despite the show making it appear that the work was done in an afternoon, it likely took a week to a month to gather enough paper (and plastic) to coat the Steam Gorilla thoroughly.
While Senku's timeline benefitted from the extra helping hands and his knowledge of chemistry, Main's methods are much closer to reality and show the real difficulty -- including how much time is spent sitting around and waiting for it to finish one step before moving onto the next.