The DNP Rx1 may have a setting to do a single 2X6 strip
but you will be using the same amount of media/ink that is used
for a full 4X6 strip. You do not save anything making only 1 print.
That printer (as far as I know) doe not have a 1X4 paper size available
and the Sparkbooth software does not have any layouts for 1X4 size.
YES DNP (a while ago) made it possible to print single 2x6 strips
but they do not tell you that doing so uses the same amount of media
as a full double strip 4X6 print... you save nothing.
In the end when your media runs out, you will have 1/2 a roll
of paper that can not be used.... you can not purchase
media separate from paper. YOU WASTE 1/2 your paper