I have discovered there must be a dozen way’s to do inserts, including the one in t-shirts. I have done the ones in sweatshirts which is done just like a dress insert and is in the how to’s. You can do inserts on t-shirts with-out cutting the window or cut the window and insert. So in order for me to help you better which method would you like to see first. I plan on getting to all of them sooner or later._________________