It's spooky season again! And paired with my enthusiasm for things that fascinate me, I dived a bit deeper into my newfound love-hate relationship, “multishade” printing.

Why hate? Because this is the result of ~20 hours of "pain" with different 2D and 3D software trying to get this to work and look nice. In the end I think it was totally worth it though!

Info about the print and technique

The idea behind it is to print layers of black or white (or even other colors) below layers of a certain color to get the effect of having a new shade, darker or brighter. It's a very similar principle to inkjet printing.

I want to give proper credit because obviously I'm not the one who “invented” this (although I haven't really seen anything like this go viral so far). I got the idea from working on our PrusaSlicer GitHub, where a feature request was made asking to implement this into multimaterial painting. The author of the issue linked this Reddit post from early 2022, and that's where I got the inspiration from.

To be very honest, although I love how it turned out, currently this is just way too much work to make it viable for some quick, nice-looking props. Except if you plan to mass-print them of course.

Workflow

If you want to try it with your own motive, this is what you'll need:

Image-editing software with vector capabilities (e.g. Illustrator, Inkscape)
3D modeling software with SVG import (e.g. Blender, Fusion360)
Printer with multi-color printing (e.g. Prusa MMU, Mosaic Palette)
Time and ambition

Find a nice motive, ideally as vector (it will save you a lot of time and headache) or create your own one. If you want to use a pixel image you'll have to use edge tracing or recreate the image from vector shapes.
Find suitable filament colors and print swatches in a layer height that gives you the colors you want.
Apply the colors from the printed color swatches.
Export the vector files and import them into your 3D modeling program. Clean up the mesh and make sure everything's tidy.
Export the 3D files and import them into PrusaSlicer. Duplicate the layers in the correct heights to achieve the colors from the swatches you printed. This will be more tedious depending on the complexity of your model and the number of shades.
Print!