Hopefully not! I should have proof of that today hopefully. Ninjaflex printed at 100% infill is pretty hard to stretch at this thickness, and even when not completely tight on the pulley it gripped very well, so I'm hoping it will stay that way. Time will tell!

This current belt is just flat, if it proves to be up for the job I will experiment with printing some with HTD5 tooth profiles, although If the belt does stretch, the teeth could just do more bad than good...