In keeping with the thinking that the object is supposed to educate people about the filament, I thought about coming up with an object that also helps to educate about the source material, which in this case is derived from the wood fibre of trees. I find many people misunderstand how a tree grows.
I thought about making a nesting tree similar to the nesting Matryoshka Dolls from Russia. Rather than splitting the tree horizontally like the dolls I could split it vertically so that each layer could slip over the previous layers branches much like a jacket. Each layer would represent a different stage of the trees growth. The layers could also alternate between the two filament types to provide some contrast in the colour.
One challenge would be to print the branches so that they have enough strength and do not sag during the printing process. They could not be perpendicular to the trunk. The branches would have to be at a minimum 45-degree angle from the vertical axis so that there is enough support as the printer adds layers.
Since the outer layers of the tree will be hollow there is concern about the thickness of the layers. If they are too thin they will flop over as they are printed. Temporary supports may need to be printed in conjunction with the pieces to add strength. They could be removed afterwards. Rafts would also be necessary to provide a strong base for each layer. Again they would be removed after the printing process is complete.
The base root structure would show off the possibilities of 3D printing that could not easily be achieved with injection moulding or CNC routing. At the very least the base would make for some interesting beverage coasters.