Ceramic molds have been used to make pottery and other ceramic objects for centuries. Today, those working in ceramics have many materials at their disposal when using ceramic molds, including concrete and plaster. Whatever the material, ceramic molds determine the final shape of the ceramic object, and as such are responsible for the character and function of the piece.

Ceramic molds are made by pressing the desired object into clay, creating a form, and then pouring a casting material (such as plaster) onto the clay and over the object. Once dry, the plaster is separated from the clay with the use of a chisel or wedge, and the object is removed. This leaves an impression in the plaster that can be used to make hundreds of other identical objects.

Ceramic workers must have durable molds that will hold up to many uses. Quality ceramic molds are also made to ensure tight seams and good reproduction. Some manufacturers offer locking devices such as keys to keep the pieces of the mold from shifting during casting. Since a mold will be used many times during its lifetime, it must be made of high-quality plaster or concrete of at least 1/8-inch thickness.

Concrete molds are used to cast pavers and decorative lawn ornaments, and they also have industrial applications. Rubber and aluminum molds can be used to create pre-cast concrete forms. For pottery and ceramics, plaster molds are common, although other materials also work well. Synthetic molds are designed to withstand the wear and tear of hundreds of castings, and generally last longer than natural, clay-based ceramic molds.