Changing default paper size on ArchiLinux

After many searches on the web, I've finally found why LibreOffice Writer always created a new document in Letter format.

Everybody on forums explains that you have to change your locale in LibreOffice options, but it was not effective.

There is an Operating System parameter for that !

Open a terminal and launch paperconf and locale LC_PAPER

$ paperconf
$ locale LC_PAPER

If you have Letter, as me, change the content of /etc/papersize to put "a4" in it:

$ cat /etc/papersize
# Simply write the paper name. See papersize(5) for possible values

List of papersize from man 5 papersize:

The following names are commonly understood by programs: a3, a4, a5, b5, letter, legal, executive, note and 11x17.
Additional paper names that one may encounter are: a0, a1, a2, a6, a7, a8, a9, a10, b0, b1, b2, b3, b4, tabloid, statement, note, halfletter, halfexecutive, folio, quarto, ledger, archA, archB, archC, archD, archE, flsa, flse, csheet, dsheet, esheet and 10x14.