Bitcoin cold storage that's more durable than a paper wallet. Use the public address on top to receive Bitcoin. Flip the wallet open to spend with the concealed private key. The qr_models.py python script generates models from your own bitcoin address and private key. See "Instructions" for more complete instructions. Note: That's not a real private key in the photo -- it's just a duplicate of the address. The address is real, however. Feel free to use it. :)OpenSCAD. A printer that can print in two colors, or some way to color the top of the model black. I used an Afinia and changed the filament from white to black when the QR code started printing. The qrcode and qr2scad python libraries: The address and private key for a Bitcoin wallet, in text form. For example, to get the address and key from a MultiBit wallet: Save all of the files for this Thing in a directory. Generate scad files for the QR codes by cd'ing to this directory and executing: Open btc_wallet_public.scad in OpenSCAD, choose "Compile and Render" from the "Design" menu, and then choose "Export as STL" from the Design menu. btc_wallet_public.scad includes the address QR code scad file generated by qr_models.py. Print the STL, using white for the bottom portion and black for the upper layers that display the QR code. I recommend using ABS filament. Open btc_wallet_private.scad in OpenSCAD. Repeat steps 3 and 4 for this file. Snap the address plaque onto the private key plaque: align the bumps on the address plaque male joint with the grooves on the private key plaque female joint and press together. Send Bitcoin to the wallet by scanning the Address plaque with Bitcoin wallet software. Hold the QR code under direct bright light when scanning. If you have an Android phone, use the private key and the Mycelium app to spend from the wallet. Choose "Cold storage" from the Mycelium menu, click the "QR Code" button, and scan the Private Key plaque. Hold the QR code under direct bright light when scanning. If you don't have an Android phone, import the private key into a software wallet, or transfer the entire balance to another wallet or account. See https://en.bitcoin.it/wiki/Paper_wallet#Redeeming_Keys_and_Withdrawing_Funds for tips on how to do this. IMPORTANT: Most wallet software does not support spending just part of the balance in a cold storage wallet. If you do not import the key into a software wallet or transfer the entire balance, you may lose any remaining balance. Mycelium does support partial spending from cold storage. See https://bitcoin.org/ for more information about Bitcoin.