· The Evil Apparitionist
You can use this free site to enlarge and print any image:If you need the enlarged files , leave me a message , because my site doesn't support bigger files.
The Sect of Homokaasu - The Rasterbator
You can do it online or by downloading the software. Either way it's free.
I've used it before and it comes in handy for printing large scale plots on a regular printer when you don't have a plotter around. It divides the image into 8.5 x 11 sheets that you tape together to make a full size print. I bought the same kit last year and made life size prints for my neighbor to cut out of plywood and foam.
I made a life size print of my son for his birthday.