i can say that a while back i bought a bunch of rolls of abs from toner plastics. all the rolls printed the same except silver. silver, if it stayed hot in the nozzle too long it would turn brown, cook and harden. you only had about 30-60sec of no print/idle time with it. purge the nozzle and get it printing right away or it was an instant clog. just shows how different pigments affect the makeup of the plastic. of course it could be that all hatchbox petg is just doomed as well..lol wont know that unless you decide to try another color.