In Chromium, as in other web browsers, there is a Print function, which includes printing to physical printers, as well as a "Print to File" function.
The default paper size for the physical printers appears to be set to the same default paper size as the printer settings in CUPS itself. So those are fine.
However, the default paper size for the "Print to File" option is set to "US Letter", and I can't figure out how to change it. This has been asked on SuperUser two and a half years ago, at time of writing, but there were no sensible answers given. I could not find any obvious issue or bug for this. Am I missing something?
My (possibly naive) expectation was that Chromium would get it from a default system setting. The obvious setting is
/etc/papersize, which happened to be set to
letter. I changed it to
a4 and restarted the browser, but it doesn't make any difference.
The version of Chromium I am using is
35.0.1916.153-1~deb7u on Debian 7.6 (wheezy), the current default version for that release.
UPDATE: Reported this to the Chromium issue tracker as Chromium browser does not allow setting the default paper size for “Print to File”, but I'm not holding my breath for a reply.
UPDATE 2: @don_crissti pointed out that Chromium got its default paper size in "Print to File" from LC_PAPER, or at any rate, it is one of the things it looks at. I verified this. I had earlier seen some stuff on the web about this, including this Mozilla bug report with a entry by our very own @derobert, but had not taken the possibility seriously enough to check it out.
Here, of course, is also a Debian bug report: Use LC_PAPER.
Extra points for anyone who can document how this is done in the Chromium source.