Clear "glass" bottle loses clearness in front of colored background So my Fiji water bottle is perfect clarity and clearness when it's by itself (as can be seen by the right most bottle). However when placed in front of a colored back ground and having a blue gradient back side label it basically turns almost black. I think it's the refraction / reflections causing it. Is there a way I can turn those down --or perhaps add a light behind the bottles that only affects the bottles and does not affect or blow out the background?



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Adding an emission light that only emits light in one direction and placed behind the bottles cleared up the issue of black bottles. However that presented the NEW issue of not allowing the backdrop to show through the bottles. As presented here: Emission Light Problem
I have had this issue before. I am guessing the problem is with light paths in render settings.  If you don't have enough bounces, then having multiple transparent materials stacked behind one another will cause the darkening.

I'm pretty sure all I had to do was increase my minimum light bounces and it was fixed.  Good luck!

Edit: Minimum light bounces for transparency is the one you want to increase