Which would it be better to store (relatively) heat sensitive stuff in, if the container will be outside but in another case. I know black absorbs more heat but shiny objects _reflect_ more heat, so which would do less damage to the contents of the container? If the container is in the sun but covered by another material is this still an issue? Specifically, I'm talking about a small metal tin inside a leather pouch. My gut says that since the metal of the container is (mostly) covered by the leather of the pouch then reflection shouldn't be an issue, but absorption still might be. That would mean the shiny metal would be the better option, but it's possible I'm missing something. (FYI, the shiny tin is shiny on both the inside and outside, which is one reason I'm concerned about it transferring heat into the contents of the container.) Opinions?