Leather cutting dies are pre-formed, metal shapes with a sharp cutting edge, used to cut shapes out of leather. They are laid on top of leather material, and struck with a maul, mallet, or hammer. The force drives the sharp edges into the leather, resulting in a cut out piece in the shape of the die.
Dies are helpful when one finds themselves cutting many of a similar pattern out by hand. An example is a wallet maker with a great design. They need many pieces to produce a lot of wallets, though cutting them out one by one by hand can be time consuming.
Leather cutting dies can be custom made to any shape or size. Generally they can be put into a clicker press for even easier cutting, or manually stuck by hand. Although there’s usually an initial investment to make or purchase a die, if it will get used often it is usually a worthwhile investment.