Hybrid Phone Case, Half NinjaFlex Half PTEG

so as I was trying to get the Ninjaflex dialed in on my printer I could tell I was going to run out. the only thing I had that was even close was the PTEG sample I had left from some Chinese manufacture.
I figure I could slide the PTEG in right behind the Ninja after it passed the Hobbed bolt, so I paused the printer and opened up the extruder and pushed the PTEG in and started it again.

Well this is the result, a soft backed phone case with harder but flexible walls. I would have taken the picture with it on my phone but dont have another camera.

just thought it was cool and that id share!

has anyone else worked with mixing materials mid print? what else would be good to do that with?