There are 2 things you need to setup
Step 1: Wifi
Select Wi-Fi Setup and connect it to your router
Step 2: Change paper size to LETTER
Airprint lets the printer dictate the paper size. So just change the paper size and that's it.
Go to SETUP
Go to PRINTER SETUP
Go to PAPER SOURCE SETTINGS
Go to PAPER SETUP
Go to PAPER SIZE
Select "LETTER" (image below is just blurry)
After you save it, just print with SeriousMD, pick Half Page on the iOS app and use a half short bond paper. It'll always be perfect.
This was setup with no prior tests. It's really this easy.
For the Mac Users:
For most printer brands, Apple would have a ready driver but for this model, it's not yet there and it's not really clear where to get it.
Good thing we're here :)
Plugin your printer to the Mac
Go to Epson's page
Download the driver then install it
Once installed, run it and you will see this
Let it download the drivers
Once done, to your Mac's System Preferences
Select Printers & Scanners
You will now see a + button. Click that to add
Your printer will be detected
In the Use: field, you will now see the driver there
Click Add
That's it! You're ready to print.