Just went to check on my proof Britannias... They have been sleeping in the safe deposit box for months. Happy to report that all of them are in good conditions with no spotting 
Coins all stored in anti-tarnish bags and then sealed in double-sealed picnic bags, stored in temperature and humidity regulated environment.
Coins all stored in anti-tarnish bags and then sealed in double-sealed picnic bags, stored in temperature and humidity regulated environment.