This print allows you to color your filament from 4 sides using sharpies (a common marker in the US). I am experimenting with different colors and filaments but the rule seems to be that the colors mix with the filament. So white filament with red marker produces a pinkish orange color, while clear filament makes a translucent pinkish orange color. Let's see what you come up with. [Update: the colors that come out of the extruder vary depending on a few things: what color filament you are using, what color and how many sharpies you use, and the heat that you extrude. Hotter temps seem to brown the color.] There are 4 holes sized to the tip of a sharpie marker. When you push the markers in, the tips should all meet at the same place. Slip your filament through the hole and watch as color is coated to all sides. I tried many different versions of this and finally feel it's shareable. This is indeed printable without support. I like to design most of my stuff that way if I can. The filament hole did not print too nicely. I had to drill it out to make it useable. The sharpie should fit snuggly in their holders. Depends how smooth your print is. If pressed in fully, the markers make quite a pinch on the filament. I recommend adjusting them so that the you can pull the colorizer along the filament without too much friction, but still getting a good coat. This thing ends up sitting atop your printer. It can hang on the filament and work fine, but the extruder ends up pulling it to the top. If you decide to mess with the sketchup file, buyer beware. I did as best I could, netfab is your friend.