Maybe the graders are just getting rusty.  This topic has been discussed in other threads.  While the operative word is "certain" it's always a good idea to research safe manufacturers and avoid older, cheaper safes that may have known issues. Data grade is probably the best suited for paper collectibles in the event of a fire.  Also, when storing paper collectibles in a sealed location where moisture might accumulate, it's advisable to monitor temperature and humidity periodically, with d