I have used the Canon Selphy printer (
(https://www.amazon.com/Canon-Wireless-Compact-AirPrint-Printing), which works great over wifi. You can print up to 4x6" or smaller formats, one image or multiple in a single print. You can connect with other apps that allow you to create collages, add borders, text, etcetera. It connects easily with a phone or iPad, a memory card or USB. Cons: you can only fit around 15 prints in the feeder so depending on what you are doing you may need to add paper. The color ink comes in film form so sometimes the overall color is a bit off. But depending on what you are doing with the photos it may not be as important.
------------------------------
Silvia Manrique Tamayo
Collections Manager/Conservator
The Wolfsonian, Florida International University
Miami Beach FL
------------------------------