Comment 4 for bug 669267

The output file format "Cairo PNG (*.png)" was used for testing Cairo output:

>> Can someone tell me why we have a non-vector format in the save as list?
>> One that seems redundant and apparently with less functionality than the
>> normal export. Is this for testing purposes?
>
> Yes, it was for testing the Cairo output. It was part of the GSoC
> project to do PDF output, and was easy enough to add, so we left it in
> for testing Cairo rendering. Now, is anyone using it for anything now?
> Bulia? I'd imagine at this point it's cruft.
<http://thread.gmane.org/gmane.comp.graphics.inkscape.user/13065/focus=13070>

To export high-quality bitmaps (PNG) from Inkscape, do not save (a copy) as "Cairo PNG (*.png)", but always use 'File > Export Bitmap…' :
<http://tavmjong.free.fr/INKSCAPE/MANUAL/html/File-Export.html#File-Export-PNG>