I am trying to change from buying blank tees to developing my own with a manufacturer out of Peru. The manufacturer wants specification sheets for the tees that I am after. I can find some specification sheets online to use as templates however I am unsure how to exactly measure the tshirt that I want. Would anyone be able to provide some measurement tips so that the tshirt specifications are correct? Also, would anyone be able to provide advice on this process to make sure that I don't end up with alot of really bad tshirts or get ripped off?! Thanks very much for your help.