In binding and finishing, any metal plate or block etched with a design, lettering, or other pattern—either relief or intaglio—used to stamp or press these designs into a substrate in finishing operations such as embossing, die-stamping, or foil stamping.
Dies for embossing and stamping are made of brass, magnesium, or copper. Brass is especially useful for long runs. A brass die used in the stamping of book covers is called a binder's brass or, when made from other metals, a binder's die. The image itself can be chemically etched, machine-cut, or hand-tooled. Increasingly, dies are manufactured using lasers guided by CAD/CAM computer software. There are five basic configurations of dies. A single-level die is most often machine-cut, and is cut to a single uniform depth. A Multi-level die has several distinct depths, and is most often machine-cut brass and is used to impress images with greater levels of detail than those created with a single-level die. A bevel-edge die has a single uniform depth, but the edges of the image are usually hand-tooled at an angle, commonly 30º:50º. A sculptured die has many varying depths across the image. A stamping die contains a single-level relief image and is used for foil stamping. The non-image area is usually recessed at a depth of 0.060 inch.
The term die is also used to refer to a pattern of sharp blades or other cutting tools used to cut a particular pattern into a substrate in the finishing process of diecutting. The most common type of die used in diecutting is a steel-rule die. See Diecutting.