No, they are not air-tight. The most recent generation of PCGS holders are wster-tight, but air has smaller, slippery molecules.
-----Burton
Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/
50+ year / Life / Emeritus ANA member (joined 12/1/1973)
Life member: Numismatics International, CONECA
Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club
Owned by three cats and a wife of 40+ years (joined 1983)
Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/




















