I need to change the Magento default pdf Header from "Invoice n 201700009 - Invoice date 06/01/2017" to "Receipt n 201700009 - Receipt date 06/01/2017".
I think that the file is the following:
/app/code/core/Mage/Sales/Model/Order/Pdf/Invoice.php
I have tried to replace the string 'invoice' on line 108:
$this->_beforeGetPdf();
$this->_initRenderer('invoice');
And the following string on line 133:
$this->insertDocumentNumber(
$page,
Mage::helper('sales')->__('Invoice # ') . $invoice->getIncrementId()
);
But nothing change in the printed invoice.
Found the solution. It was pretty easy, just override this inside:
code/local/Mage/Sales/Model/Order/Pdf/Invoice.php