It is possible to make settings for custom sized paper. The following procedure explains for Windows WordPad as an example of how to print on custom sized paper for a specific application.
Be sure to load paper in the paper feed tray.
Display the data to be printed.
On the [File] menu, click [Print...].
The [Print] dialog box appears.
Under Windows 7, click [Print] on the [WordPad] menu.
From [Select Printer], select the printer.
Click [Preferences].
The [Printing Preferences] dialog box appears.
In the [Original size:] menu on the [Print Settings] tab, click [Custom paper size...].
The [Custom Paper Sizes] dialog box appears.
Enter the paper size in [Short edge:] and [Long edge:].
Specify [Measurement Unit...] if required.
Select [Place as portrait] or [Place as landscape] according to the paper orientation.
Click [OK].
The screen returns to the [Printing Preferences] dialog box appears.
Click [OK].
The screen returns to the [Print] dialog box.
Click [Print].