How to print images two-sided using `lpr`?

Question

I have several photos, which I wish to print on a single piece of paper. I have already tried:

• Using convert to combine all images per side. However, now I need to print them two-sided.

• Using convert to combine them into a single PDF for some reason results in each page being extra long, with the top half being blank, and the bottom half containing the image I need. See example of one such page below.

• If these were EPS files rather than images, I could combine them into a single file before printing them two-sided. However, this is not an option for image files.

• Even combining them into a single TIF file would not allow lpr to print them two-sided.

• Naively sending them to lpr two files at a time, such as via

  lpr -o sides=two-sided-long-edge file1.tif file2.tif
  

  results in them being printed on two separate pages, since the system creates a separate lpr instance for each of the files.

Note: Conversion packages with a 2 in the middle, such as img2pdf and tiff2ps, are not available on my system.