Established (EST.) Metal Design Stamp. Design is approximately 3mm. This professional quality stamp is manufactured to the highest standard for durability and alignment. This stamp is made of hardened carbon tool steel for decorating all types of jewelry items including our metal stamping blanks. Can be used on silver, copper, brass or other metals. Face ImpressArt logo toward you, when stamping; to ensure all of your design stamps come out right side up.