Many people have asked me to share the files for the lithophanes I'm creating. I don't personally create the lithophanes myself, but use a web based tool that has a ton of granularity to its configuration. I will link this tool below, and have included a photo of my model settings in this post. I'm not positive it matters, but I've been sticking with 16:9 images and haven't had any inconsistencies in model size. However, a different resolution could result in a mis-sized lithophane for these models I am sharing.
When printing the model, I am printing the base and the lithophane as one object and using an M600 command to pause my printer to change from the filament for the base, to the white necessary for a lithophane. I personally chose to add a border to the lithphane to give it a clear beginning and end to the image, but you could certainly disable that functionality. I put the lower border of the lithophane inside the base, and perform a plane cut on the top, as it overhangs too much to print successfully on my printer.
Tool to create lithophane: http://3dp.rocks/lithophane/
Set the "Model" tab to "Outer Curve" and set your model settings to those depicted in the attached image and you'll be good to go. Oh, and under "Image Settings" it defaults to "Negative Image" which you'll need to toggle to "Positive Image."
To light the lantern I'm using some LED puck lights from Amazon, any should do that are 8.5cm in diameter or smaller. Here's a link to the exact ones I'm using: https://www.amazon.com/gp/product/B079DLVJM8/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
If anyone has questions, please feel free to ask.