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Repeat after me, kids: "Cello is permeable to air and water vapor!"
It's for protection of the wrapper leaf. It works fantastically well for that purpose. It does not affect or impede the humidification, acclimation, aging, etc. of a cigar in any way I've ever been able to notice.
Ten years ago, I picked about a half-dozen different types of cigars, and for each type I got six out of the same box, stripped the cello from three of them, and put them all away for aging. About a year ago, I began to smoke through these samples. I'd give a friend two identical cigars, one with cello and one without, and then I left the room and he'd remove the cello from the one cigar, then Sharpie A or B on the bands, at random, remembering which letter was which but not telling me. I returned and lit both cigars, alternating puffs A, B, A, B. I could never detect any differences between them, even after nine years of aging with and without cello.
Leave them ON!
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