MicroSeed

MicroSeed is a Bitcoin self-custody hardware product that shrinks metal seed backups: it stamps the 12 or 24 BIP39 words one letter at a time onto a one-inch (25.4 mm) stainless steel or titanium washer, a part available at any hardware store, so the backup medium can be restocked at will, draws no attention, and never has to be shown to airport security the way a metal seed plate does.

The product is a stamping jig: each letter position has tactile registration and the jig is specified to under 0.1 mm accuracy, addressing the misalignment that ruins most hand-stamped backups. Beyond standard mnemonics the published specifications also cover SLIP-39 Shamir backups, hexadecimal strings and ASCII text, with a total capacity of about 240 characters. Finished backups are waterproof, fire-resistant and corrosion-proof, and can be split across multiple hiding places. Purchase accepts Bitcoin on-chain and Lightning as well as cards, and the team is registered in New Mexico.