Foil Armor 2-Way Humidity Control Packs are designed to prevent trading card curling and warping by maintaining a consistent 65% relative humidity. Perfect for protecting foil, holographic, and high-value cards, these packs flatten warped cards and preserve condition over time. The 8g pack is ideal for flattening up to 5 cards within 24 to 48 hours or for long-term storage in sealed containers. The 33g pack handles up to 10 cards in 48 to 72 hours or can be used in larger containers for long-term use. Each pack lasts up to 6 months depending on exposure and includes an easy-to-read indicator card that shows when it's time for replacement. Just place the pack with your cards in a closed container—no activation or setup required. Made with only glycerin and water, Foil Armor contains no harmful chemicals, making it safe for all card types. Whether you're storing cards in top loaders, slabs, or binders, Foil Armor ensures reliable, mess-free humidity control. Trusted by collectors and professionals, it's the simple solution to keep your collection flat, fresh, and preserved. Foil cards are especially sensitive to moisture because they are made by bonding layers of paper and foil. When humidity levels are too low, the paper contracts more than the foil layer, causing the card to curl inward. When humidity is too high, the opposite occurs. By keeping the environment at a stable 65% RH, Foil Armor prevents these imbalances and keeps your cards flat.