How are fonts rendered in cups?

[Josh Dukes]

Ok, I see there's a FontPath directive, like the one for X (unlike X it's not set), but the default path contains almost no fonts. So I'm wondering, how does cups render fonts? What's the flow? I've read the wikis on ipp and cups, but I still don't see it.
So depending on the program interfacing with cups, the file will either be sent as a prerastered image or as a simple text file. From the amount of time it takes and the size of the transfer, my guess is that Adobe Reader sends a rastered image, whereas Evince sends the raw pdf which is then rendered or whatever on the cups server, then sent to the printer. Now I'm assuming that in this case the cups client sends all the fonts needed when it sends the pdf and it doesn't care what fonts the print server has, is this assumption correct? Could I speed up printing by adding the fontpath of our font server to cups? And what about printers that have fonts, does cups know about them?
Thanx for any information you have.