Taming Canon Selphy Edges
Long story short, the Canon Selphy photo printer crops your images.
If you want to know exactly where the edges of the paper will cut through your image, I have done some experiments and came up with a .PSD file where you can easily place your image, once you resize it to 1658px X 1131px.
When printing, select “Scale to fit Media”, although this should not alter the image, as the DPI matches (300dpi); but that’s how I ran the measurements, so better safe than sorry.
Download the PSD here (no trick, really, it’s a share URL on my Dropbox).
Let me know how this works for you! I came up with it and tested the method using my Canon Selphy 910.