What is a Lithophane and how do they work!?
Here is an excerpt from Wikipedia on the origins of lithophanes:
"The word "lithophane" derives from Greek "litho", which is from "lithos" which means stone or rock, and "phainein" meaning "to cause to appear" or "to cause to appear suddenly". From this is derived a meaning for lithophane of "light in stone" or to "appear in stone" as the three-dimensional image appears suddenly when lit with a back light source."
The lithophanes I'm creating aren't porcelain or stone, but PLA plastic which is 3D printed. The final product is a thin sheet of plastic which has different thickness's to allow more or less light through when backlit. Below is a short video of several of my lithophanes before and after backlighting.
What is light color and how does it affect a lithophane?
Does color temperature really matter and what is it?
This is a picture of the Kelvin scale: 1000-2700K is similar to the light emitted from a sunrise. 3000-3500K would be a normal warm household light bulb. 5000-6000K cloudy, but sunny and 7500K+ would be a blue sky. I backlight my lithophanes with one of three LED color ranges, 2000-2500K, 3000-3500K and 5000-6000K. The backlighting plays a huge role in the way the final product looks!
What is a 3D printer and how do they create lithophanes?
I create my lithophanes on FDM (Fused Deposition Modeling) 3D printers. They work by melting plastic and extruding it through a very small nozzle. The nozzle lays the plastic down layer by layer, typically each layer is .1-.2 mm high. As an example: if a lithophane is 113mm tall and printed at .1 mm layer height, it would take 1,130 (ONE THOUSAND one hundred and thirty) layers to print the entire lithophane. You can cut that in half by going with a larger .2mm layer height but you sacrifice and lose quality/resolution. The majority of my lithophane prints take anywhere from 24-50 hours to print just ONE.
For each layer the printer melts/extrudes plastic onto the print bed with a specific profile/pattern. If you're familiar with CNC machining, the profile (G-code) would be what you would call the tool path. This profile is what changes the amount of light coming through the lithophane and makes it look like the original picture when backlit. The thick spots are dark and thin spots are light as they allow more light through.
I generate all my STL (stereolithography) files using as high of a resolution as my slicing software will support. Generally HD (1920x1080) is the optimal resolution I try and use. I print at a very high resolution (.1 to .12 layer height) for the majority of my prints. I'd rather take the extra time and get the lithophane to look as close to the original picture as it can. The combination of creating the STL with optimal resolution and then printing it at .1 to .12 layer height generates the best possible quality lithophane you can achieve from an FDM printer. Sometimes it's hard to decipher if you're looking at the original picture or the lithophane itself!
Have a question?
This section will be receiving updates frequently to address questions you have so please keep checking back! I want this to be a learning section for both you and myself. I learn something new about 3D printing everyday and am CONSTANTLY trying new things and learning better methods to improve my print quality for lithophanes. Please feel free to leave a question or comment below!