I just received an order of custom transfers from F&M Expressions that has a pressure recommendation of 60 PSI. I went to their website and the transfers are recommended to be pressed at 50-60 PSI (firm). Can someone translate what that means for a Hotronix press? Mine has numbers like 1, 2, 3, etc. I looked at the Hotronix and Stahl's websites and couldn't find a translation of PSI to numbers.