Air-tites are, because they aren't airtight. Many collectors (especially of copper) feel that coins need to breathe, or else the problems caused by contaminants already on the coin will run rampant. I believe bronze disease, for one, would be accelerated. (sorry I took so long to reply, forgot about this thread!)
Thanks, Are Intercept 2x2 considered safe? I have lincoln proofs 1959 and on in Intercept 2x2 since I wanted to preserve the redness.
What do museums and larger collectors use to keep their collections safe and secure for the elements, maybe we could learn a bit from them. I'm guessing their solutions are quite expesive, but it's worth making a few calls about. -DJ
This is from Brent-Kruger site regarding Kointain Holders. I don't know how true it is though. "It's no wonder that the Smithsonian Institution used Kointains for the National Numismatic Collection. After its formation, the American Numismatic Association's Money Museum chose Kointains for much of its displayed collection."
Kointains and half Kointains are commonly used for display in museums with numismatic material. For storage they use acid-free 2x2 paper envelopes, with the writing them done with an archival pen, then they place them in coin boxes that are changed periodically.
Not all museums are so careful with their coins. Some things have changed in recent years, but in years past the Smithsonian used to clean the coins - I mean polish them right up with a rag - on a regular basis. And they didn't always use archival quality storage materials either. Some still don't.
Me and Just Carl must be the only ones here that still use the Whitman Classic Albums. I do have one Dansco though, only because Whitman doesnt make a Classic album for Half Dimes. All of my high dollar coins are individually wrapped into the middle of large duct tape balls and buried behind the shed......lol