I prefer using icing (frosting) sheets.
I have a Canon MG5320 and it prints the colors perfectly. I use basic Microsoft Publisher to snag photos (being mindful of copyrights) or just lay out photos. I do find many public domain photos when searching.
I like the brilliance of the icing sheet. I place my images directly onto wet flavored royal icing. The photos/ images dry as colorful as printed.
I have wafer paper but I have not used it at all.
After reading comments I will try it again using piping gel.
Great discussion.