DougyFrisch
+1y
File>New 12x15 inches @300dpi
You'll have to ask you t-shirt printer what size screens they use. That will be your limit to shirt sizes. My printer always likes my files to be 12 by 15 so they scale really good on shirts and they'll fit on my big shirts. keep in mine how things are going to look when you print on a small shirt and then when you print on an XXL, you might want to do several sizes to make things look right, but that's up to you.