I needed a new profile image. While I'm proud of the project that lead to my former "TV face" image, it didn't really say "Thingiverse"

Having just successfully created a 3 color bottle opener, I knew the time for a multi-color portrait had come.

This is my first attempt at mashing colors together on the same layer like this. I'm really happy with the results. Hopefully others will take this technique and run with it. Turns out you don't need dual extruders to make a multi-colored part!

tv-face: http://brettbeauregard.com/blog/tag/hdtv-mount/
3 color opener: http://brettbeauregard.com/blog/2011/09/three-color-3d-print/

This was a fairly involved process, so I'll break it into "Image Processing", "Printing", and "Finishing"

Image processing

1. There's probably a really easy way to turn an image into 4 colors using GIMP, but I couldn't find it. So I used http://obamicon.me instead. Kind of cheesy, but exactly what I needed

2. Using Inkscape, I turned the image into 4 separate color paths using the trace bitmap tool (Scans=4, stack scans = false)

3. The trace tool creates splines, which are incompatible with the next step. To get rid of them I modified each color path in turn, selecting all the nodes at once then clicking "make selected segments lines".

4. I then saved each color path into a separate DXF.

5. Using OpenSCAD I was able to extrude each color to the thickness of one Z layer (0.36mm in my case) and put them into separate STLs. I wanted to print these on a base for easy removal, so for my base color (white) I created a rectangle 2 z-layers thick, then put the white extruded path on top of that. The other colors started at Z=0;

Printing

1. The first color was printed as normal.

2. I then edited the Z-offet in the motherboard settings to be 2 layers higher (smaller) than before (0.72mm in my case)

3. When Skeining the remaining colors, I unchecked "Activate outline" on the outline tab.

4. The remaining 3 colors where then printed one at a time at the modified Z-offset, without outline being activated.

Finishing
If you look at the closeup you can see that I put WAY too much plastic down during this print. A little sandpaper made the image much crisper. in the future I'll need to play around to find the Skeinforge settings that work best.

Also, by printing black last I left myself with a little streak as the extruder nozzle left at the end of the the print. An X-acto knife took that right off.