writing into the 3d print

[Roxy]

Does this give a good separation of colors, or does the new color often bleed?

Also, does the higher level need to be much higher, so as to give you a visual signal that it's moving there?

The colors do not bleed. But it takes time to switch from one color to another. Check out:

http://3dprintboard.com/showthread.p...ight=Roxy+iris

You can see the black letters laid on top of white. And then you can see how long it takes the black to fade back to white if you look at the side of the iris box.

And... If you are running Marlin firmware, you can have the printer stop at the right time to do the filament change:

http://3dprintboard.com/showthread.p...ltipanel-Users