Sunheat - 'stretchtesting' ..and the winner is....

Hanging in the sun for many days during a heatwave in our country.
Rings are hollow, thickness of the material only 0.5mm across. Outer diameter of the rings 150mm(6")
There's a load of 1 liter bottle filled with water hanging on each ring.
Materials -from left to right- black XT, bleu nGen, black PLA, white PLA.

Only white PLA withstand this kind of heat. It only sags just a little bit during this torturing test.
Even better would have been using white XT or nGen I suppose.

That may be because white reflects the heat.. A fair test would have white nGen and XT as well