Project — Coinbook · 2025–2026
A seed phrase on paper burns, fades and gets lost. Coinbook is a 40 × 40 mm stack of 316L stainless-steel plates that stores up to 24 words — stamped into the metal, closed with four screws, sealed with a serialized band.
01 — How it works
Nobody else should ever see a seed phrase — so Coinbook ships as a kit and is stamped by the owner.
02 — Development
The stamping jig is the core of the product: it locks the plate at every row and column, so a hammer blow can't land a letter in the wrong place. It went through a series of SLS-printed prototypes — letter geometry, plate registration, stamp guidance — before the production version.
03 — Videos
Recorded during production in Shenzhen.
04 — The kit
Everything nests into a molded 2-in-1 case with a metal lid. The underside of the box doubles as a QWERTY stamp stand — each of the 35 steel stamps in a labeled slot.
05 — Specifications
06 — Comparison
Most steel backups hold loose letter tiles in rails — tiles can be rearranged or fall out. A stamped letter is part of the steel.
Common stamping jigs align one line at best; spacing is judged by eye. The Coinbook jig locks every position in both axes — higher density, consistently readable.
Name and phone number on the visible outer plate, so a finder can return it. The phrase sits behind the serialized seal and four screws.
