> Okay. Basically the problem is that conversion from PDF to PS get’s
> really complicated at some point, and results in really large PS
> files.
>
> I’ve tracked down the responsible commit to be
> cf2ae39e9d93c2dcdc50afd7d0389c314898273c, which implements
> transparency for PDF. Now this seems plausible, as transparency is
> NOT part of the Postscript specification, and Adobe and GS have just
> added (very volatile) methods to the PS specification for
> transparency in a created PDF file.
>
> So when we have a PDF with transparency we cannot really convert it
> into proper Postscript. Thus such a conversion appears to rasterize
> the entire page, resulting in a very large ps file (of lower optical
> quality) that is hard to render.
>
> But this probably means that your PDF viewer does not handle PDF
> properly but instead converts the PDF to PS and displays that. That
> is nothing Lilypond can influence, apart from maybe handling
> transparency in a more intelligent way such that transparency is
> only used if it is called for. But the best way would probably be to
> use a proper PDF viewer.
Maybe this deservers a comment in the manual. And maybe it deserves
an issue in the bug tracker, too.
Werner