I live in a place where humidity usually ranges from 40–70%, depending on weather, season, plants, people, etc. It often goes over 60%, but I’ve never had issues with mold. I ventilate daily (windows open), which helps when the weather is good, though on rainy days humidity can rise instead of drop.
Since collectibles are stored away (less airflow), I want to minimize risk and ease my anxiety. My current idea is using near airtight containers with silica gel + hygrometers, aiming for 40–50% RH. I know dry cabinets are optimal, but they’re not practical for me (space & budget).
I’d love to hear any tips, experiences, or alternative methods others use to control humidity for storage. No matter if its general information on the humidity problem or specific solutions & tips about the method with airtight containers & silica gel pads.
Silica gel inside a non-airtight containers is always a good idea. I tried running some experiments with them though, and while they should work decently as buffer, it’s better to not overestimate their capacity to hold air humidity.
Also they should be regularly reactivated with heat, so the color-changing ones should be preferred.
The most effective and practical thing would be to buy a dehumidifier, which can totally reduce the water content of an entire room for like $100. Aiming for 45-50% RH like you said, is perfect
Another useful thing is to regularly open and ventilate your boxes: air flow is extremely important too when preventing mold. If you see a chill and dry day, that’s the best time to revisit your collection!
The theory behind my choice is that a non-airtight box allows some movement of humidity in case too much moisture is trapped inside. This could happen when, for example, you handle cards in a very hot day → close the box → air temperature drops in winter and water can’t escape outside, condensing.
Another factor to consider is the possibility of inks, cards themselves or plastic off-gassing. The acid nature of such gases could damage cards, although it theoretically requires years.
if you search there is a ton of information about humidity and storage, here’s a thread I found helpful
My question is, how did so many JP grails survive years in Japan when most people didn’t care to control the temperature or humidity of their closet for decades?
If I had to guess, it’s because humidity/mold damage is not as likely as you might expect. I think most of us who find ourselves on this forum are hyper concerned about the longevity of our collectibles, which is a good thing, but we might also be overly fearful.
I don’t know if its as extreme as we think. I have a bunch of boxed gameboy games, and the cardboard boxes are excellent, and even the corrosion on the metal contacts is pretty good. Well, I’ll just say the ability to clean them and the failure rate for some 25+ year old games is quite low. Especially considering high use games like pokemon are slotted in and out a lot.
yes i’ve read through them and it does motivate to actually get a dry cabinet. A room dehumidifier works wonders too, of course, as long as its not noisy
Yeah it might be the optimal solution. Acceptable sizes are not cheap, but to be honest having an electric dehumidifier is, from an energy consumption standpoint absolute overkill.. especially if the place you are living in doesnt suffer from mold or humidity problems.
Mold is a very rare occurrence, so I’m not surprised that many JP cards survived in great conditions. Still, we know from other hobbies how to properly store collectibles or cardboard materials, so I don’t mind being nerdy about these things
Warping and curling are much more common though, and can happen even to pristine cards which graded PSA 9/10. Many people don’t even consider it a damage and so, it isn’t frequently reported. I’m personally bothered by cards becoming like pringles, so controlling humidity is worth for me
The best, most reliable solution is to buy a large dehumidifier for the room where you store your cards. Get one that is made for 1,000+ square feet so that it can work quickly and efficiently for the space allotted.
I would also recommend buying temperature/humidity monitors. You can set them up throughout the home. They’re very cheap and accurate.
But as SeasidePokemon said, and as I have said previously, the danger of humidity and mold is overstated by collectors due to anxiety. Most collectors live in a way that is not conducive to growing mold. If you do notice mold or mildew growing in your home, then your cards are definitely in danger.
Silica gel or packs are entirely useless after being exposed to air. You can buy rechargeable beads but otherwise silica is basically no better than a prayer or incantation
Appreciate this thread and the comments! I’m also primarily based in a humid part of the world. A dry cabinet would satisfy the paranoid part of my mind, but the challenge is that I like to display a lot of my collection. I’ve kind of settled on periodically rotating slabs for display and then keeping the rest in a slab case (although the comments here are making me consider using less airtight boxes..) with silica gels and relying on the fact that AC/small dehumidifier keeps the overall room humidity reasonable if not 100% perfect.
