Q: Airprinting on epson xp600

Not all apps support AirPrint.

As an example type a new Note then tap the Action icon (box with a right facing arrow) bottom of the Note window.

See if the Print icon appears.

There are some troubleshooting steps here: http://support.apple.com/kb/HT4356?viewlocale=en_US&locale=en_US

Check using the panel on your computer to be sure you have the latest firmware on your printer and update it if necesssary.

Make sure the printer and iPad are connected to the same network.

Reset the iPad (hold down the home and sleep buttons, wait for the Apple logo, let go of the buttons), the printer and your router.