spree/spree_print_invoice — pull request #49 by ssendev (2014-04-03 17:59:23+00:00)
Title: added config option for prawn (allows setting page size, margins)

to use just add
`Spree::PrintInvoice::Config.set prawn_options: { page_layout: :landscape, page_size: "A4" }` in an initializer