Formatting for Virtue Mart Invoice

[Rob_M.]

For VM 3.0.4

Where and how do I format the PDF invoice (vminvoice) I receive after a customer places an order.  For one, I don't know why it's an invoice, shouldn't it be a purchase order?  I need to make some of the columns wider so descriptions will fit.  And would like to say Purchase Order instead of Invoice.

thanks