Ever since I bought my Pixma Pro 200 I have not had one photo print correctly from Lightroom or the Canon software. Paper doesn't matter. The only thing that prints correctly for me are notecards. I have double checked printer settings in the software and on the printer itself, but it always prints with wide margins and never fills up the whole page within the designated borders. (Don't get me started on borderless printing). Perhaps it's user error. This is my first professional printer and I like the quality of the prints, but I can't understand why I don't have full control over my prints. The image I have provided was printed on 8x10 MOAB Slickrock Metallic paper and I have the correct ICC profile selected for this. This paper has a slight curve to it, but I have evperienced the same results with flat paper as well. You will notice that towards that edge I have a black line and its stats to smudge. When the printer takes the paper in, it seems to roll the paper back before printing. Almost like it's trying to correct itself. Any help would be greatly appreciated.
I have a Pro-100; you can look in the On-Screen manual for your printer for a similar table by searching for Print Area.
The printer will have certain prescribed minimum margins. If you want equal margins you would need to configure your print dialogue so that all four margins are at least as large as the largest printer prescribed margin. Then you need to either crop to the appropriate cell size (by subtracting the margins from the paper size) or by Zoom to Fill.