How to add additional details and shipping method to packing slips?

Hi,

We want to be able to print our orders in bulk but the only option is to print the packing slips but these are missing shipping method and additional details which appear on our order page? I have downloaded shopify order printer app but it only allows printing of packing slips or invoices. I can customise these but no idea how to add the code? If anyone can help it would save us a lot of time.

Many thanks