After EXTENSIVE research on my part (and it will be worth EXACTLY what you are paying for it
) I vacuum seal my entire cellar.
I had to repack some of my tins and cans so I had to open the vacuum sealed bags and discovered that always, without exception there would be a waft of tobacco smell from round flats and rectangle flats. ALSO, WITHOUT EXCEPTION there was NO waft of tobacco smell from any of the Paint can style (Peretti, Comoy's) or the pop top small cans (G.L Pease, SPC) OR the pop top tall cans (Rattray's, etc.)
When I resealed, I decided not to vacuum seal any of the paint or pop top cans.
No Smell to me means no transference of oxygen or moisture.
Seal the Eso's leave the Peretti's
"Leave the gun, take the Cannolis."