well this is just a really simple idea its nothing specific, but theres this paper you can get from office works, its called transformation paper and you can print whatever you want onto it using an ink printer then iron it onto a shirt or whatever-its not expensive. Its about 20 Australian Dollars for a Packet of 5 A4 Sheets of paper, its really easy and you can do anything with it.
ive use it a lot of times but if you print it on a stretchy thing like a tshirt or the print is full rather than just the outlines it kinda breaks after wearing it, its really cool if you want to print like your name on a tshirt or something like that but if your graphic is big, the first time you wash it it will fall apart. but i guess there are better quality papers to work with, ive only used HP inkjet paper though
i was told by a guy who does these on t-shirts for a living..
you can use Epson Durabrite printers. they use durabrite inks.. made of waterproof pigment that doesn't crack/fade under 100+ washings. he says in the States, the printer version C88 costs $80 only
he says Avery papers are good if you want to make a few shirts. you can do transfers on both light and dark. but if you want to make a lot more t-shirts, say up to 15, he likes the company bestblanks.com. It's like $25 for a set of 25 sheets.. cheaper. And they don't peel or crack if you use it with the Epson Durabrite
I've never actually had a problem with big images cracking, even after a wash. It happened once on a small image. It was on a streachy tight singlet though, and the image was on my chest so it cracked a little bit.