Metal vs. paper backup: protecting your seed long-term
Paper burns at 233°C, ink fades, water destroys it. A metal plate resists 1500°C, water, and time. To protect a seed for 20 years, it's the only reasonable choice.
When you buy a hardware wallet, you generally receive a small paper card to write down your seed phrase. This is sufficient to get started — but in the medium term, it is far from perfect.
The limitations of paper
Paper is fragile against three well-known enemies:
- Fire: paper ignites at 233 °C. A domestic fire can easily exceed 800 °C.
- Water: water damage or prolonged humidity erases the ink and damages the paper.
- Time: over 10 or 20 years, the ink fades, the paper yellows, and becomes brittle.
Most compromised paper seeds are not due to an attacker — but to forgetfulness, humidity, or moving. A risk that materializes silently, until the day it is needed.
The metal alternative
A metal backup is a stainless steel or titanium plate on which you engrave (or assemble with letters) your seed phrase. The result:
- Resists over 1,500 °C.
- Impervious to water, humidity, and corrosion.
- Practically unlimited lifespan.
Which format to choose?
Two main families of metal backups coexist on the market:
Engravable plates
Cryptosteel Capsule style: you stamp letters into the metal with a dedicated tool. It's more laborious but ultra-robust. No moving parts, no risk of disassembly.
Assembled plates
Trezor Keep Metal or Ellipal Mnemonic style: you insert pre-stamped letters into slots. Faster to set up, and just as sturdy once closed.
For most users, an assembled format is more than sufficient and saves 1 to 2 hours of setup time. The time saved is significant when making multiple copies.
Best storage practices
Whatever the format, keep three principles in mind:
- At least two copies, in two geographically different locations.
- Never next to the wallet they protect — otherwise, a burglary takes everything at once.
- Not with someone incompetent in security — prefer a bank safe deposit box to a relative who might misplace the plate.
For significant crypto assets, combining these backups with a multi-signature architecture further strengthens the resilience of your security — see also our guide to getting started with a hardware wallet.
"A metal backup costs €50 to €150. It's the life insurance for your crypto assets. The math is simple."
Protect your seed from time
Stainless steel plates, titanium capsules — resistant to fire, water, and time.
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