Crystal Humidifiers....PG Solution?

[Krish the Fish]

Does anyone really have any definitive proof that 70% is "ultimately" the best for cigars? I'd be surprised if such proof (in the form of scientific evidence/research publication) exists. 70/70 is so widely said because it is easier to remember than say "65%, but higher for some cigars and lower for others."

This is all imo of course. No proof for what I just spouted out either.