How to center an image on a page with lp?

OS is Debian 10. I'm trying to print a batch of images with lp. So far so good. Scaling works great, for example. Right now I'm printing with: lp -d "$printer_name" -o ppi=100 -o position=center 1.png However, positioning is not functioning. Leaving position off centers the image top to bottom, but puts it on the left side of the page. position=right has the same result. position=center has the same result. position=left has the same result. position=top puts it at the top left. position=bottom puts it at the bottom left. It's like lp just can't move the image over to the right side of the page for some reason. What is going on here? Printing in gimp or firefox works correctly and I can definitely print on the rest of the page.