Made a simple holder for lithophanes that you can use led strips to power. I used 3dp.rocks website to make the lithophane and set the max size to 150mm/ outer curved / 3mm thichness / Positive image.

Printed lithophane using this tutorial: https://www.youtube.com/watch?v=y63sVpeViXo&t=357s

Printed holder with 0.2mm layer and 20% infill.

Supplied my own lithophane soo people can compare and make the correct size.

I used 5v led strips that i can supply with usb power. PS. the lithophane will need to be either wedged to stay put or use a bit off hot glue on the backside to hold it in place in the frame.

Also supplied a version without cutouts for the lithophane soo that people can print the entire thing as one piece. To do this just move the lithophane soo that it touches the top of the holder in your slicer. I would recommend to have several prosesses so you can change the infill after need.