Thanks for your great plugin.
I'm currently extending it to support a second template so that the user can print either an "invoice" OR an "packing slip". I have a user who needs both to be separate templates.
Would you like to include the modifications in your plugin (please) ?
I also added tags (functions) for phone number and the custom order_number provided by this plugin: http://wordpress.org/extend/plugins/woocommerce-sequential-order-numbers/
I know, there's a premium plugin doing this... and I'll always prefer plugins on wordpress.org ;-) Thanks again for saving me some time today.