if GL1 is not a canon printer profile i dont know what is ?
Don't get shirty, we like to be polite here
Sorry to say but you don't, GL1 is not a Canon profile description or file name, see attachment below for what they actually look like and their location on a Windows machine.
As far as I remember "GL1" is a paper code; a profile should have coded reference to paper and printer.
When you said you had to "kill magenta" that certainly told me that your colour management set-up was wrong with respect to the profile. Canon profiles are pretty good and would not require such drastic adjustments, in fact none at all; so you are doing something wrong.
The Canon paper profiles are likely to be on the disc that came with the printer and were probably installed when you installed the driver, have another look.
his printing is very complicated art, you would have thought by 2010 this could have all be simplified by all manufacturers but again this would be to easy .
Most of us here do photographs of real subjects so colour reproduction is vital too. Colour management standards are controlled by the International Colour Consortium (ICC) to avoid manufacturer "custom" methods and inconsistency. CM does need to be learnt and understood, I suggest you do a Google search and read up on the basics, there is much science in the background.
I previously asked about your monitor calibration, I'm now wondering if you have the monitor profile correctly set up in your software. PS, like Qimage, needs the monitor profile, printer profile (paper specific) and rendering intent to be set for full colour management, in addition to the driver having the correct settings.
Terry