Best free software for printing on CDs/DVDs?

So, I’ve got this printer that handles printing directly onto CD/DVD media—specifically a Canon EOS Rebel. When I picked up the printer, it came bundled with some proprietary software for disc printing, but honestly, it’s just not hitting the mark for what I'm trying to do.
What I’m actually looking for is something more flexible—software that lets me layer text and images together in a custom layout that fits my specific vision. The catch? It has to be free. My boss is being pretty stingy and won't authorize even a single dollar for extra software.
Does anyone have any good recommendations or ideas?

I’m not really following you—if you’ve already designed the CD label, what exactly is the holdup with the printing process? Usually, if you use one of those free labeling programs, the only real headache is whether your specific printer model actually supports it. It’s basically just a hardware compatibility thing at this point:

http://www.cddvdlabelmaker.com/
http://www.nchsoftware.com/cdlabeler/index.html