Mould on Pokémon cards: what to do, and what never to

Finding fuzzy growth, powdery spots or a musty smell on a card is alarming, and the instinct is to wipe it off fast. That instinct is exactly what makes it worse. Mould is a containment problem, not a cleaning one, and the right first moves are about stopping it spreading, not scrubbing it away.

First, recognise it

Treat it as mould, not dirt, if you see any of these:

• Fuzzy or powdery growth on the surface
• Spots that seem to be spreading over time
• A musty, damp smell on the card or its storage

Mould is alive, and it's a collection problem, not just a single-card problem. Spores travel, so a mouldy card near your other cards is a risk to all of them.

What to do

The goal is isolation and a dry environment:

1. Isolate the card. Put it in a clean, closed, inert enclosure on its own, away from the rest of your collection.
2. Dry out its environment. Mould needs moisture. Get the storage area dry and keep it that way; humidity is what let it start.
3. Handle it as little as possible, and wash your hands after. This is a health matter as much as a card one.
4. Photograph it and get it assessed before any treatment.

That's genuinely it for the owner. From here, safe removal is a conservator's job, not a kitchen-table one.

What never to do

This is where cards get destroyed trying to be saved:

• Don't wipe or brush it. You'll smear spores across the surface, grind them into the coating, and spread them into the air and onto other cards.
• Don't use bleach, alcohol, peroxide, ozone, UV or a "mould spray." These can damage a composite card, discolour it, and still leave spores and staining behind. You get the harm without the fix.
• Don't use a damp wipe. Adding moisture to a mould problem is feeding it.

The reason professionals don't just wipe mould off is that wiping fails on both counts: it doesn't remove the spores and it does damage the card.

How it's removed safely

Proper mould remediation on paper items is a dry-capture process, careful HEPA vacuuming with low suction and a protective screen so the nozzle never drags across the fragile surface, done in appropriate containment. It's precise, low-contact work, and it's why a valuable mouldy card should go to someone equipped for it rather than getting a wipe-down at home.

Where we come in

We handle mould as a containment-first job: isolate, assess, and remediate with low-contact technique that protects the card, then clean and stabilise the surface. As with every card, you choose the treatment level, grading-safe conservation for anything you'll send to PSA, or full for private collections, and we're clear about what a mould-affected card can and can't come back from.

If you've found mould, isolate the card now and don't wipe it. Then start an order and we'll take it from there safely.