So I was moving stuff in my office closet and got out a Rubbermaid container with proof sets. The container had all my proof sets and a bunch of family photos. I looked at my 1988 and 1990 proof sets and saw this cloudy hazing around the rim of the proof dollars. My other coins in the proof sets looked fine, but I threw 3 silica bags in the container and placed it back in the closet. Looked like the proofs got a little oxidized. Those cases may have been a little weak to allow air. The proof sets have moved from different locations and containers for decades. Life goes on as I deal another first world problem!
Some of government’s inserts are not inert. Many Proof sets, like the 1970-S, are notorious for promoting toning on the cent. A large number of silver Proof Ike dollars from 1971 to 1974. I would not get too upset about the 1988-S Olympic dollar. It’s one of ugliest and least desirable designs ever. It’s one of those bullion coins.
I don't think they are 100% air tight, and gases can get in there and create hazing and toning. (Just my opinion.)
