Comment # 12 on bug 954884 from Johannes Meixner

I assume with your d00236-001.save PDF file
from your attachment#656341 [details]
the command
------------------------------------------------------------------------
$ gs -r50 -sPAPERSIZE=c5 -dFIXEDMEDIA d00236-001.save
------------------------------------------------------------------------
shows on the screen what you get as printout
on paper with c5 paper size.

For more information about Ghostscript commands see
"Test if what the application had submitted to CUPS seems to be correct" in
https://en.opensuse.org/SDB:How_to_Report_a_Printing_Issue

For "Paper sizes known to Ghostscript" see the file
/usr/share/ghostscript/*/doc/Use.htm
or at Ghostscript upstream see
http://www.ghostscript.com/doc/9.15/Use.htm#Known_paper_sizes

I assume when you let Ghostscript rotate it
e.g. via a command like
--------------------------------------------------------------------------
$ gs -r50 -sPAPERSIZE=c5 -dAutoRotatePages=/None \
 d00236-001.save  -c "<</Orientation 3>> setpagedevice"
--------------------------------------------------------------------------
then it looks on the screen as you actually would like
to get it printed on your c5 envelope.

Regarding how to let Ghostscript rotate it you may have a look at

http://stackoverflow.com/questions/3089773/how-to-change-page-orientation-of-pdf-ghostscript-or-postscript-solution-neede

In any case the crucial point is that what LibreOffice produces
as data for printout must match the printable area of the paper
on which it should be printed.

The printable area implicitly defines the orientation:
For example when for A4 paper (size 595 x 842 PostScript points)
the printable area is 15 22 580 820 then it is "portrait"
in contrast to 22 15 820 580 that is "landscape".

Cf. "Background information and explanation - PostScript" at
https://en.opensuse.org/SDB:Landscape_Printing

Therefore it also depends on the orientation how the paper
is loaded in the printer device.

For example when you load A5 paper into an usual printer that
can print up to A4/Letter paper size, then it could be possible
to load the A5 paper in two ways into the printer:
With its short edge in front ("portrait") or
with its long edge in front ("landscape").

Depending on the orientetion how the paper is loaded
in the printer device the application must produce
data for printout that fits in the printable area
of the paper as it is loaded in the printer device.