Thank you breadman for your reply - to get my 12x12 to print correctly - borderless - I ended up choosing 13x19 as my print size, moving the margins to 0, adjusting the paper guides all the way open, and putting my cardstock all the way to the left. ...
Why is borderless printing not available on custom paper sizes? That is absolutely ridiculous. And why is this not pointed out by Canon? Instead, they go out of their way to lie with this gem: "Take your cherished memories to the next level with ...