AirPrint to any printer (without official AirPrint support) using Ubuntu and iOS

This is an update of my previous AirPrint escapade to get AirPrint working with Ubuntu 12.04 and iOS / OSX using a generic printer. I'm still using the Epson SX600FW and SX610FW family which have both been great to date, I spent an hour updating the config to enable AirPrint compatibility. Read on... 

iOS AirPrint without a true AirPrint compatible device

My latest iOS mission has been to enable Apple AirPrint introduced in iOS 4.2 to work with non AirPrint printers. At the time of writing I am only aware of HP printers that are AirPrint compatible out if the box; therein lies the problem since poor experience with HP and Canon consumer printers in the 90's has left me a staunch Epson owner ever since. 


Epson at the moment have no AirPrint enabled devices available and have taken the stance that they will not be retrospectively updating firmware for existing models to enable AirPrint support. I've only recently acquired several variants of the Epson SX600FW family which have been great to date, so being keen to maximise their potential I spent an hour or two 'enabling' AirPrint compatibility using an Ubuntu server to act as an AirPrint server. Read on...