Stippling on metal objects or sheets is done via a hammer and punch device. Punch devices take the form of objects with sharp, tapered points, such as nails, needles and pins. Copper sheets, which provide the least resistance to stippling, is a popular medium, while steel sheets provide the highest resistance.
Before the metal is punched with the punch device, in a method referred to as piercing, the design is often traced onto the medium. Tracing typically involves attaching a paper to the metal piece and then piercing the outline with one or more types of punch objects, which can be of various sizes to create different holes. Different pressure can also be applied to generate holes of varying depth.
Metals can add a range of color and brightness to a design, depending on the kind of metal and depth of the piercing. Copper sheets, for example, provide various levels of contrast and light based on hole size.