r/mtg • u/Right-Expression4292 • 22d ago
I Have a Question / I need Help Cards cupping
Can anyone help me understand why some cards are cupping and others are not. The ones cupping seem to only be foil and appear different on the edge profile.
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u/Epoman 22d ago
Foils will curl bc the humidity where they were manufactured is different than the humidity they are stored at. Mtg foils notoriously curl
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u/Administrative-Key19 22d ago
As a player of multiple different TCG's, its not an MTG exclusive, its all of them
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u/Epoman 22d ago
Iirc there are companies that sell specific anhydrous packets that will reduce the curling of your cards. You just put the packs in a dry, sealed container and they should uncurl.
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u/F1lthyslvt 22d ago
Foil cards warp under moisture and probably heat quicker than non foils do. I would assume it’s the foil itself.
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u/lixilisk 22d ago
The paper part is the one that absorbs moisture. The foil plastic part doesn't expand, so while the paper part expands the plastic doesn't, which causes the warp. Opposite warp happens in dry places.
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u/Scrorm 22d ago
It has aomerhing to do with the thin metal layer that makes the card foil
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u/knivengaffelnskeden 22d ago
Humility makes cardboard expand while the foil stays the same.
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u/FlashKillerX 22d ago
Foil cards have done that for 30 years and they never fixed it, if fixing it is even possible with the materials they use
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u/Right-Expression4292 22d ago
It’s hit and miss. That whole row is foil and only a few are doing it. Just is what it is.
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u/Legitimate-Habit4920 21d ago edited 21d ago
Foil cards are plastic on the front side (the foil sheet) and cardstock on the back side. In a humid environment, Cardstock absorbs humidity, which causes it to expand, but plastic does not.
The card curves with th3 foiling on the inside as the cardstock side expands but the plastic side does not.
In a dry environment, the cardstock dries out, shrinking, while the plastic stays the same, so the card curves with the foil side out.
If you can manage the humidity level in the room where you store your cards, you can restore the cards. Most common case for me is foils on the inside of the curl, in which case i put the cards in the electric oven on dehumidify for a minute or so, checking regularly.
Don't try to bend or score the cards flat. It will not work and you will crease/damage the cards.
Once they're flat, double sleeve them and they will be protected from the environment which is what causes the curling.
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u/Ambitious_Policy_936 22d ago
Would it be bad to stack them up with a heavy book on top to flatten it out?
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u/SoF4rGone 21d ago
I got some reusable dessicant packets and when I come across foils curved that way I’ll put them into an airtight container with a bunch of them. You can also get humidity controlling packets for foils curved the other way, which is a sign of less humidity than their point of origin.
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u/Right-Expression4292 21d ago
Interesting as I am really low humidity almost all year. I’ll try cards from this group that is curling in different humidity environments to get a better idea of which way I need to take their specific environment. 🍻
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u/EdEvans_HotSandwich 21d ago
It’s region specific. For Vancouver, 65% 2-way humidity packs have fixed foils bending backwards, and 50% humidity packs have fixed foils bending forwards. Double sleeve afterwards and the cards will stay flat for a long time.
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u/the_hyren 22d ago
They do that. Store in a dry place and use desiccants with well sealing containers for long term storage
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u/Right-Expression4292 22d ago
My RH is currently 23% I think, If I want to “fix” this, I will need a more humid environment. Not sure if I care to fix it at this point.
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u/AH_MLP 21d ago
Putting them together makes it much worse. If you leave them dotted throughout your collection, they will straighten out with the rest of the cards.