Pepe said:
[Zip-logs are moisture barriers, hence] I think using zip locks are fine if you are packing properly moisturized cigars in them.
Two things:
Thing 1: Zip locks are imperfect moisture barriers. They're pretty good, but they're not perfect. For our purposes (a few weeks in the mail), moisture content of cigars doesn't change much in the zip-bags. (This is why cello is left open on one end, btw.)
Thing 2: Shrink-wrapping a "properly humidifed" cigar such that its moisture content doesn't change only works if the temperature doesn't change. If the cigar is (say) 65% when it leaves my house at 70F, and it gets to 105F en route, it'll dry out, a little (RH will go down.) If it arrives at your place and sits on the porch at 55F, it will get more moist, may even suffer condensation.
A lot of you probably already know this but, just in case, I thought I'd mention it.
You want your cigars at ~65% RELATIVE humidity. (Some say 70%, because they sell PG. That's typically considered "close enough", although many cigars are much better at 65%.)
Thing 3 (ok, I lied
): You can tell that zip-locks are imperfect because, when you open the tupp, you smell cigars. If they were perfect moisture barriers, you wouldn't smell anything.
Thing 4 :lookup: : Putting humidity control in the tupper is a good idea. It won't be perfect, but it will help mitigate the rediculous RH-pressures that cigars experience between the belly of a plane at ~30F and the back of a UPS truck at ~105F. Now everyone just has to remember to pack for no movement, so things don't bounce around