Epson EPL-1220 Reference Manual page 32

For Windows Users
To print on the custom-size paper, specify the paper size on the
printer driver, and set the paper size switch to Others on the MP
tray.
1. Access the printer driver and click the Basic Settings tab.
2. Select the User Defined Size from the Paper Size drop down
list. The User Defined Paper Size dialog box appears.
Chapter 2 Paper Handling 32