Change the pdf document file name
The file name of the pdf document is:
Title of the pdf (what you entered in the 'title' field)_order/invoice/shipment/credit memo number(s).pdf
Eg. PACKINGSLIP_10000001-10000005.pdf is the name of the file where 'PACKINGSLIP' is entered as the shipment pdf title, and which includes packing slips 10000001, 10000002, 10000003, 10000004 and 10000005.
Multiple documents will be combined into the same file, or you may wish to print pdf documents one at a time - eg. PACKINGSLIP_10000001.pdf, PACKINGSLIP_10000002.pdf, PACKINGSLIP_10000003.pdf and so on.
To change the name of the pdf file, change the title of the pdf document.