I wonder what is the best way to show big amounts of text in library. Our usual means are not an option.
There are too many good ways, prolly not one you may call "best".
1) You can bind text to a variable like:
temp = "Some really long string"
show expression Text(temp, **google renpy text properties/style for a lot of options)
2) Screens are a very easy/convenient way:
screen show_text():
text temp size 15 color black yada, yada, yada (parameters again)
This will be the easiest way of you need a cool background as well. You can use add/frame/window for that.
3) NVL Sayer, that works ok as well, we had an example of Nigerian Spam letter at some point if you still remember presented in that way

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There are prolly more but these three are definitely the best Ren'Py has to offer. Other options are prolly class/func but that would be an overkill.