Go into the receipts admin (under templates) and copied the location of the standard foxycart css file.
<link rel="stylesheet" href="https://your_foxycart_store_domain/themes/standard/styles.css" type="text/css" media="screen" charset="utf-8" />
Paste it in a browser window and copied the css into my own file.
Wrapped everything pasted in the following and then name print.css and uploaded to the server.
@media print{
...
}
Go into receipt template admin and paste the following right beneath where foxycart's is called.
<link rel="stylesheet" href="http://your_domain_here.com/print.css" type="text/css" media="print" charset="utf-8" />
In above code media is changed from screen to print.