[XeTeX] Windows views XeTeX PDF with bad font size

[Khaled Hosny]

On Sat, Feb 18, 2012 at 09:37:44AM -0600, mskala at ansuz.sooke.bc.ca wrote:
> I'm sorry I don't have many details because it wasn't my own system on
> which the problem appeared, but:  I have a PDF file generated with XeTeX
> (xdvipdfm), and a Japanese font embedded in the PDF.  It looks fine on my
> screen (under Linux, with a couple of different viewers) and it prints
> correctly when I send it to my laser printer.  But when my friend tries to
> view it on a Windows machine, he complains that "there's not enough space
> between the characters" and from the screen shot it's apparent that the
> viewer has scaled the font to a too-large size while still positioning
> each glyph at its correct reference point.  As a result the glyphs touch
> and overlap.
> 
> Most likely this is some problem with the Windows PDF viewer.  I've seen
> similar things before though not as extreme as the current case - it may
> have some standard sizes, and round things to the nearest standard size
> even if that's a bad idea, as a result of trying to make pixel hinting
> look nice.  But if there's anything I can change in the way I generate the
> PDF file (or by editing the font) to make this issue less likely to occur
> on Windows systems, it'd be valuable to know about.

One possibility is that you are using a CFF-flavoured OTF font with a
non-1000 EM which will render with inflated glyphs on certain versions
of Adobe Reader (not only on Windows). This seems to be a xdvipdfmx/AR
bug (luatex had it too, but IIRC correctly it was later fixed). If this
is the case, AFAIK the only solution (sans fixing the driver) is to use
a different font or a different viewer.

Regards,
 Khaled