I assume it's going to be at the bottom of the listed enumerations for Rolls on
https://msdn.microsoft.com/en-us/library/windows/apps/windows.graphics.printing.printmediasize.aspx?f=255&MSPPError=-2147217396. I think you should test with Roll04Inch and see if you can force it to work.
If not, you can set the PrintMediaType to continuous and see if you can just print within a specified margin. It may be worthwhile to ask on a printing-specific forum.
Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.
NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with
undefined objects and unknown namespaces.