I have been working on trying to find a way to keep registration on both sides on the clear materials. I haven't been able to find a way to do it consistently enough to offer them to my customers.
flat bed or roll printer think op has the idea right (UV color / UV white / UV color)? so the stick side has no ink yes it two print jobs using the same origin and not removed between prints. first print reversed with white fill over second print normal way round, now depending on colours and density of white is how successful it will be.
as far as registration is concerned lock the graphic within a box the box to be identical in dimension for the both prints this takes away inconsistencies of size because of bleed strokes etc. so its the box complete that is registered, prove it within the art package by putting the two graphics on top of one another just to check then send the two separate graphics to the rip as long as you dont change any settings between the two rippings with return to origin ticked on the first.
second print could include the cut path.
sadly the roland white is just not strong enough for this but is how i do something similar but involves laminating white vinyl and a final cut path.
oh the reason for asking if roll or not was that some cling films are not stable enough when heated whilst printing and the return is off a bit.