Foil Magic: The Gathering cards are premium versions of those cards that feature the normal cardboard backing with a foil mylar layer on the face of the card that creates very shiny artwork. These cards are worth a premium price due to both their rarity and their visual appeal.
However, foils are also prone to "curling," which is when a card begins to have one side flex outward while the other retracts inward. Foils can curl in either direction, folding inward toward the artwork of the card or folding outward toward the back of the card.
Today we're looking at what causes foils to curl, and how you can flatten your foil cards back to their normal shape.
Curling used to only afflict cards after they had spent a long time in suboptimal storage. But in recent years many Magic players have found extremely curled foil cards within brand-new booster packs. This is understandably frustrating for anyone who wants to actually play with their foil cards.
Humidity (moisture in the air) is the biggest reason why foil cards curl. Since the front of the Magic card is made from mylar, it won't expand or contract when exposed to the moisture in the air. However, the back of foil cards are still made from cardboard and will expand or contract based on how much moisture has been absorbed into the material. If you open a curled foil in a fresh booster pack, that means the humidity where you are is significantly different from the humidity where the card was printed. The modern scourge of curled foils is most likely due to a difference in climate between where Wizards of the Coast prints cards now, and where they printed them historically.
If you are in a particularly humid environment or if the material of the card seems to be holding excess moisture, the cardboard backing will expand while the front of the card stays the same size. This causes the corners and edges to curl inward toward the foil face of the card. If you place this card on a table, the center will be touching the table while the edges of the card will curl upward and not touch the table.
Conversely, some cards will resist moisture better than others based on the material, or if the environment you find yourself in has a dry climate. In this situation, the cardboard backing of the card will contract inward while the foiling stays the same size. This causes the edges to curl toward the cardboard backing of the card. If you place this card flat on a table, the edges will touch the table while the center of the card will bow outward away from the table.
If your foil is only slightly curled in either direction, try placing it in between the pages of a heavy book and then stack a few more books on top of that. After leaving it under the weight of the books for a day or two, inner sleeves (also known as perfect fit sleeves) will help to keep your cards flat. These are small sleeve-like casings you can put on your cards that fit inside a normal-sized sleeve. Not only will inner sleeves help to resist the card's natural tendency to curl, but they will also create a more airtight environment to prevent further moisture from reaching your card.
If the edges of your card are curling towards the cardboard backing, you will need to add moisture to your card. There are safe ways to do this without watering your cards like houseplants; we certainly don't recommend introducing your cards directly to water in any way, shape, or form.
However, there is a type of packet that can help regulate the air near your foil cards and keep them from curling. These packets are referred to as humidor packets, which maintain a consistent, desirable moisture level when stored near your cards. These can help prevent foils from curling or even uncurl some of your foils that have already started to curl.
If just storing humidor packets with your foils isn't doing enough, you can build a makeshift rehydration chamber to maximize their effectiveness.
You will want a sealable, air tight container to create the main portion of your rehydration chamber. Using a see-through lid or container is beneficial, as it will let you track the progress of your foils as they go through the flattening process. You will want to have a raised flat platform on the inside of your container for your card(s) to rest on without directly touching the bottom of your container. The platform should be rigid and preferably waterproof as well. I recommend a deck box or clear plastic case for your platform if you are using a small chamber. Place your platform into the center of your chamber.
Place your cards onto the center platform. Around the edges of the platform, add humidor packets as necessary based on the size of your chamber. For smaller chambers you will likely only need one humidor packet whereas for larger chambers you may need two or more! The moisture content of a card will vary based on individual cards as well as the climate of your region. A card may take a few days to begin to flatten, so we recommend checking on the card periodically while it is in the chamber. A see-through container comes in handy as you do not want to open the chamber while a card is inside except to add cards to or remove them from the chamber after rehydration.
A card may not be perfectly flat when it's removed from the chamber—let it acclimate to the open air for a few minutes after it leaves the chamber. After letting it sit, insert the card into an inner sleeve, and then into a regular sleeve. This will limit the amount of air the card is exposed to and will slow future curling from occurring. If you'd like, you can place the sleeved card under some books or something flat and heavy for an extra day or two for good measure.
If the edges of your card are curling towards the foil face of the card, you need to remove some of the excess moisture from your card. Silica packets are the best way to remove moisture from your cards, and can be stored directly with your cards in a deck box or a card storage box. Silica packets will help remove the moisture from the immediate area surrounding your cards. You can find these packets in some of your food products that need to resist moisture or online where you can purchase in bulk quantities. These packets will lose their effect over time, so I highly recommend replacing them semi-regularly, likely on a bi-weekly or monthly basis.
If the packets aren't doing enough on their own, you can maximize their effectiveness by building a dehydration chamber.
For a dehydration chamber, you will want to follow all steps outlined for building a rehydration chamber with one major difference: instead of using humidor packets, you will want to use Silica Packets. This will help remove moisture from your cards to flatten them when the edges start curling toward the foil face of your card.
Some foils will have more severe curling issues than others. Drastic times call for drastic measures. If you have tried all of the other options listed above and are unsuccessful in your efforts to flatten your foils, there's one more option left to try.
You can use a comic book press to flatten out your foils. This is not something to be reckless with when using it on Magic foils, as if you use the press incorrectly you can damage your cards. You will want to place parchment paper on the comic book press, and then place the card on top of this parchment paper layer. Layer another piece of parchment paper on top of the card, "sandwiching" the card between the two pieces of parchment paper. Place a comic book backing board onto the top layer of parchment paper, to ensure the card is protected while being pressed. You will want to have your temperature be set to 170 degrees and let it press for 15 minutes or 900 seconds*. After pressing has been completed, make sure to let the machine fully cool before removing your card.
*Note: The optimal temperature and time for your cards may vary depending on your local temperature and humidity, and the temperature and humidity where the cards were printed. We recommended you try this process a few times on less expensive cards first, before trying to flatten your id="Jeweled Lotus" variantId="226670"!
Foils can have extremely high prices compared to their nonfoil counterparts, so we don't recommend using expensive cards on your first try at flattening any of your foils. Many of these potential uncurling processes are going to vary based on climate and other factors specific to your region, so it is absolutely necessary to try these methods out on some of your bulk foil cards before trying the process with your expensive foil cards. By taking this approach you will be able to make any necessary adjustments to the process or find out if any of these methods simply do not work for you.
If you have tried everything and still have curled foils, there is one final option left for you. You could just make your deck using exclusively foil cards. It may be an expensive fix, but at least your cards will look shiny!