Steel vs Paper

Paper is the simplest seed phrase storage option and entirely adequate for most people. A piece of paper, written clearly in pen, stored in a secure physical location — a safe, a locked drawer, somewhere not obviously connected to Bitcoin — does the job.

The limitation of paper is physical fragility. Paper burns. Paper floods. Paper degrades over decades. For smaller amounts or for people who live in areas with low fire and flood risk, paper is fine.

For larger amounts, or for people who want additional physical security, steel offers significant advantages.

Steel seed phrase storage products — sold under brands like Cryptosteel, Bilodeau, and Coldbit — allow seed phrase words to be stamped, engraved, or assembled onto a metal plate. Steel survives house fires, floods, and physical damage that would destroy paper.

Testing by the Bitcoin community has shown that some steel products survive temperatures exceeding 1,400°C — well above the temperature of most house fires. Others have been submerged in salt water for extended periods without degradation.

A middle ground option: laminate the paper. A laminated seed phrase is water-resistant and more durable than plain paper, at virtually no cost.

A few principles that apply regardless of material:

Store it away from the device. If someone steals your hardware wallet and finds your seed phrase in the same location, they have everything.

Consider a second copy in a different location. One house fire shouldn’t mean permanent loss.

Don’t label it obviously. A piece of paper labelled “Bitcoin seed phrase” is a target. Something filed neutrally is not.

Tomorrow: the passphrase — the optional 25th word that adds another security layer.

— The Daily Bit