Here is my desing for a 55x55x63 cubic lithophane lamp.
The 4 lithophanes panels should be 44.5x53.5mm for a thickness of 2mm max.
It is printed in two parts, the top part holds the LED strips (RGB/white/NeoPixel).
You can optionnaly use a TTP223 touch sensor if you choose to use a microcontroller to drive the LEDs.
The bottom part hold the microcontroller, It has a small slot to secure an ESP8266 D1 mini.
The two parts are attached with 4 small M2.5 screws and heat set inserts.
Here is the code if you want to create the full version with adressable LEDs, microcontroller and touch sensor: