I am generating svg files with my own application, and using inkscape in command-line mode to convert to pdf.
If any of the filled polygons are transparent (opacity < 1), the time taken to print the resulting pdf *greatly* increases
(on my Linux system). Inkscape doesn't seem to obey the @media rule in the css section. I've tried to use

@media print {
...
}
@media screen {
...
}

to vary the fill of certain polygons depending, but Inkscape doesn't seem to honour the media type.
I can change my app to modify the css portion depending, but I was hoping to just provide a multi-purpose css file.

Any thoughts?

Thanks
neal