NFC (Near Field Communication) stickers generally do not work well directly on metal surfaces. This is because metal can interfere with the radio frequency signals used by NFC technology. The metal can block or reflect the signals, leading to unreliable or weak communication between the NFC sticker and a device.

To make NFC stickers work on metal surfaces, you can use specialized NFC tags that are designed for metal applications. These tags typically have a special design or shielding to minimize the impact of the metal on the NFC signal. They may have a foam or plastic layer to create a gap between the tag and the metal surface, allowing for better communication.

If you need to use NFC stickers on metal objects, make sure to choose NFC tags specifically labeled as "on-metal" or "metal-friendly" to ensure proper functionality. Regular NFC stickers may not provide reliable performance when applied directly to metal.