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.)
It's my understanding that some gases can actually go thru plastic. That's one of the reasons we pay so much for plastic gas cans. They are made with layers of different types of plastic.
I perused through ebay at these Prestige Proof Sets, and almost all of them have hazing around the dollar coin. Their casing, although attractive, had had a manufacturing issue.
