Can you enlarge the pictures to whatever size you need on you Canon? If you can, do that and make a print in whatever size you need. Then cut a piece of freezer paper to a standard 8 1/2 by 11 inch size and iron it the back of the fabric you want to print on and run it through your Canon. I haven't done tea shirt fabric but it works brilliantly with cotton. When using cotton I often just iron the top couple if inches or so to stabilize the fabric as it starts to go through the printer. I use a Canon printer as well. If my method doesn't work for you, go to the Canon website. They have great technical support.