How do I know which edible ink cartridges to get for my printer? I'm a cake deco hobbyist and I want to start printing photo cakes for friends and family. The edible photo systems online look pretty expensive, but I hear that you can buy a cheap Canon printer and then just buy the edible inks and paper. But how will I know which edible ink cartridges match which Canon printer??? Please offer specific, simple instructions. I'll TRULY appreciate it!