How to print a photo as a folded card

You need to use an image editor that can handle layers. Here's how I do it with Photoshop Elements:

1 - print the card to a pdf file in Photos.

2 - convert each page of the pdf file to a jpeg image with Preview.

3 - create a blank image in an image editor that's 8.5 x 11, 300 dpi, borderless.

4 - place the front & back image (1st page) in the upper lefthand corner.

5 - place the inside pages (2nd page) in the lower lefthand corner.

6 - hide the 2nd page layer and print the 1st page layer.

7 - flip the paper over end for end (do not flip side by side), hide the 1st page, unhide the 2nd page and print.

This will give you a 5 x7 card

As an alternative. Create a blank white image in the same size orientation (landscape/portrait) as the image you want on your card. Print both images side by side.

Like below if one of those images was blank/white.

If you want an easy way to create a blank white image, create a duplicate of the image you want to print, then edit it, turn exposure and highlights all the way up to 1. Contrast and black point all the way down to -1, then drag a point on the middle of the curves line up as close as you can get to top left (see edit panel screenshot).

Another option

Export the image and print it from an office program like word or power point (or the free equivalents) where you can easily position the image on the page.

Yes, you could use Pages for my method instead of an image editor.