How do I edit the printed invoice template
 

Hi, I wish to have the words Payment Receipt added to my printed invoice ( not the online or emailed one) . I include a copy of the order invoice with the orders but need it to reflect that it is a reciept and that no funds are owing. I do not wish to purchase a new mod just add this to the printed invoice template but cannot find it...can someone please let me know what it is called in my version and where I need to add my text. Thanks...