What does a cryptocurrency wallet hold?
A cryptocurrency wallet manages keys, addresses and transactions. Bitcoin and other asset records remain on their blockchains, not inside a metal plate or electronic device. Consider both everyday use and recovery if a device becomes unavailable.
A custodial exchange account is different from a wallet whose keys you control. Not every service gives you a seed phrase to keep.
Cold wallets, hot wallets and hardware wallets
- Hot wallet
- Uses keys in an internet-connected environment. Convenience comes with the need to secure the device, software and operating environment.
- Cold wallet
- Keeps private-key storage isolated from online environments. The key questions are how keys are held and transactions are signed.
- Hardware wallet
- A dedicated device for key management and transaction signing. Connection methods and security designs vary by product.
- Seed phrase plate
- A physical medium for recovery information. Plate B does not generate keys or sign transactions and does not replace your transaction wallet.
Why does a cold wallet need a backup?
A device and its backup solve different problems. Even with a cold wallet, consider what happens after failure, loss or a reset. For a self-custody wallet that uses a seed phrase, complete and accurate recovery information matters.
A compatible replacement device may restore a wallet, but not every word-based backup works with every wallet. Confirm the format before choosing the backup material and location.
Check compatibility before marking
- Check the actual backup standard, not only the wallet brand.
- Plate B supports 12/24-word English BIP39 phrases. SLIP39, multi-share backups and other formats require separate confirmation.
- If you use a passphrase, preserve it according to the wallet maker’s instructions, along with any necessary account or recovery settings.
- Understand the marking system and check your draft before permanent punching.
Read the seed phrase and BIP39 introduction, then follow the Plate B marking guide.
What to look for in a metal backup
Start with accurate recording and readable recovery. Then compare material, thickness, loose parts and the intended storage environment. Paper, digital files and metal have different characteristics; no medium replaces correct operation.
Plate B records words using punch marks in a solid 3 mm plate of 316L stainless steel. Review the full specifications and material and security guidance for your own backup plan.
Whatever wallet you use, never share the seed phrase with support, strangers or a website asking you to “verify” a wallet.
Sources and further reading
BIP39 — Mnemonic code for generating deterministic keys