A lithophane is a piece of art made out of a translucent material that produces a grey tone image when backlit. Thinner sections allow more light, thicker sections allow less light. These have been around for a long time, but are now relatively simple to make using a 3D printer.
The basic process is to take a photo and process it in such a way to create a 3D model that the thickness of different sections is dependent on the brightness of a pixel.
There are a variety of programs and applications that simplify the process, including just opening an image in Cura. I opted for an online version: http://3dp.rocks/lithophane/
Image Prep
- Choose an image. Want something with decent contrast and not too much detail.
- Convert the image to greyscale. (I used GIMP.)
- (Optional) Autolevel the image so it ranges from full white to full black. (Also in GIMP)
3D Model Creation
4. Upload the modified image to the conversion tool.
5. Under the image settings, make sure it’s set to Positive Image. (Bumpy side out, brighter sections thin. The default is negative image)
6. Choose you shape and size. (I used the Outer Curve, with 100 mm max size.)
7. Refresh to get a preview.
8. Download the stl.
Slicing
9. Orient the model so it prints upright.
10. Choose a low layer height (I used 0.15 mm)
11. Set infill to 100% (and type to rectilinear)
12. Add a brim to help with bed adhesion.
13. Set a slower print speed. (
Printing
14. Use a light colored filament. (PLA tends to be better detail)
15. Keep an eye on the print.
When it’s done, put a light behind it.
https://www.instagram.com/p/CE7JIUbhAIx/
I searched a variety of sources, but couldn’t find any comprehensive comparisons/recomendations for print settings. The vertical orientation tends to be better for detail (and the only way to print curved ones), but it does have a greater likelihood for adhesion issues or getting pulled off. Printing slower seems to be the best way to mitigate that. Would love to hear if others have experience here.