How can I print two packing slips on one page?

In the interest of using less paper, I am trying to figure out how to print 2 packing slips on one page. I often print multiple order’s packing slips at once, then fulfill them all at once. I don’t want to use a full 8.5 x 11 sheet of paper for a packing slip that doesn’t need that big of a paper, so I’d like to print them two to a page.
I saw how to change the format size to 4x6 (like for thermal label printers), but I not how to get them to print two to a page, side by side. I’ve scoured the community and cannot find the topic even addressed anywhere, let alone how to do what I am wanting. Can anyone help?

I would love to know the answer to this question too!