I think some of these printed versions were downloaded from https://www.calendarsquick.com/printables/free.html. I’ve seen some on Etsy sell pre-printed variations, but I’ve never tried them before. One can custom format paper outputs for printing on most printers though, it just takes some work depending on the editing software you’re using and how well they allow your printing outputs. Cutting sheets to size is certainly a way to go too.

I’ve not looked into it, but Avery may have some 4 x 6″ preformatted templates you could use in programs like Microsoft Word and then print the outputs. Look at https://www.avery.com/templates/8386, for example.