When it comes to paper, there is a paper for each case and a name for each paper. And all of them differ in their intended use.
In this article, we will focus on Ledger paper, but in general, it is only one of these paper types.
If you want to learn all kinds of paper and specialize in this, you should research other papers on Google.
I do not understand why you want to specialize in such a subject, but of course, I respect it.
I also did pointless things. And I keep doing it. Nothing can be as boring as acting with great rationality.
But perhaps you may want to learn these paper sizes for a rational reason.
For example, you are a printer. Or worst of all, you are working in a printing house and a job requiring ledger paper size has come before it.
All of these are possible. As people get older, they are surprised at less. The situation in question would not surprise me at any age.
Other paper models I like are the following.
You can also mail me your favorite paper styles. Thus, it is learned by everyone who likes which style of paper.
All size articles have been here.
I also cover color issues in this link.