Bronze die or bronze cut pasta refers to pasta that has been extruded through a bronze die, as opposed to a teflon coated die that is typically used for mass produced pastas. It's the more traditional way to make pasta in Italy, but the teflon coated dies are now more commonly used because they are less expensive. Bronze die cut pasta is considered better because it has a slightly rougher, more porous texture that sauces can more easily cling to.