With the Phrasekeeper you're able to stamp your wallet passphrase or a private key into a plate made of 99% copper to keep it durable against most common environmental influences like water or fire.
We tried to keep costs as low and quality as high as possible, therefore copper is smooth enough to easily stamp it, but hard enough for everything else.
The melting point of copper is at about 1085°C (1985°F). A standard house fire will reach a top temperature of about 1000°C (1832°F). So if you don't plan to place your Phrasekeeper near a pyrotechnics factory, everything should be fine, even in worst case.
And copper looks very cool!
Phrasekeeper is compatible with a broad variety of hardware and software wallets.
There are several packages we will offer: