I finally got around to trying my first photo puzzle experiment. I didn’t have any photo paper on hand, so I just used regular printer paper, and I used spray adhesive to stick it to 1/4" underlayment from Home Depot – so it’s not super high quality and probably won’t last long, but it’s just a prototype, so that’s okay. Mostly I wanted to test the cutting / kerf stuff, and thanks to all the great advice posted by @jbmanning5 (e.g. set the focus to half the material height), that part came out beautifully! I finished it with about 5 coats of spray lacquer – could have used a couple more, but my can was approaching empty and that was all I could coax out of it.
The photo was of my 3yo grandson eating some of his birthday cake. Here he is contemplating the assembled puzzle after he and my daughter put it together: