Hi Jamie,
I would not try it on canvas, there will be no precision. Ordinary multipurpose copier/inkjet paper will do. Although the heads should be aligned, it is unlikely to cause your problems. If you've not done so, if you can spend the time watch/listen to the link I mentioned here
http://ddisoftware.com/tech/printers/print-too-dark-turn-on-another-light/ . Basically, as I've mentioned many times before - set your monitor/display white point to match your canvas.
Best wishes,
Ray