Multi-color printer owners, how do you color an STL ?

Multi-color printer owners, how do you color an STL ? Does the STL encode color information ? Or do you have provide a separate STL for each color ?

I believe you have to generate an AMF file. I don’t know much more beyond that though. I’m interested in this as well, because I’ve got a 3-color Prusa i3 in the works.

ASCII STL files don’t encode color. Binary STL files have 2 different formats for encoding color data for triangles. None of the modeling programs I’ve used exports their models using binary STL, so I haven’t used these formats.

Makerbot printers with dual extruders will combine two separate STL models, using a separate filament (color) for each model.

@Laird_Popkin1 , AMF is supported by Slic3r which is what most people are using right now.

How do you generate an AMF file ?
Which editor supports it ?

OpenSCAD supports it:

There is an AMF editor:

And Slic3r can generate the AMF files from multiple-STLs, though it seems multiple-STLs is the way most people do it right now.

Slic3r had gcode arcs support a long while back, but it was quite experimental. Marlin also has support for it. The framework is there…just, not activated atm.

@ThantiK Have you made a multi-material AMF in OpenSCAD? I’d love to play with it, but it’s not available in the current release.

@Chris_Thompson1 yes. File -> Combine Multi Material STLs, open all the STLs you want, hit cancel when done, and save the AMF file. It’s been in Slic3r since like 0.9.6…and is indeed in the current release.

@ThantiK That’s helpful, but I’d like to design in OpenSCAD for multi material. color(); is there, but I can’t export from OpenSCAD to AMF. Then in Slic3r, I want to choose what AMF material is which filament and extruder. And then the multi extruders are messy on the hardware size. I’m looking forward to seeing your 3 color design. I’m going to make a separate post about my multimaterial ideas and suggestions.