I got some black PLA, it blocks the light 100% even with only 2 perimeters. I also tried painting my green PLA black and even with one coat of paint I was able to block out 100% of the light. So basically use black as a base paint before painting the exterior of the bat box, or go with black PLA.


Interestingly enough both black pieces warped in the sun on a 100 degree day here in Tucson. The test print I have outside in green PLA has not warped at all, I need to do some more investigation to see what temperature black PLA can handle. Of course in 100 degree weather we want the house painted white, and I suspect that will survive even a 120 F degree day.


I'm planning on printing my thinnest test tube twice in black PLA, and paint one white. I will put those two up with the green PLA to see if any will warp in the sun in a stronger circular configuration rather than as a flat sheet.


I also need to finish putting my temperature probes together. I'm 90% done, but I have a bit of work left to do. Just need to get off the couch and do it. Then I can quantify how much the color of the PLA affects the interior temp relative to the air temp.