I am not familiar with your printer, so I am guessing at the exact model, etc. According to the user manual for the PRO-2000, you cannot print borderless on cut sheets:
scroll all the way to the bottom of the page.
Since it is a roll paper printer, can't you just print your image at your desired size (borderless, across the full width of the roll, for example)? Are you trying to use sheets because of the paper type (i.e., paper that does not come in rolls).