I thought I had this all figured out but apparently not. I'm printing a 15x22.5" image on a roll of 17" Cold Press Natural. In LR, I have the page size set up with no margins and the layout with no margins except for 1/2" on the bottom of a vertical (portrait style) image for a weighted bottom border.
However, the image comes out 8mm to the left (when the print is viewed - or 8mm to the right when coming out of the printer).
What did I miss?