silver pmc tags *these fabulous tags are perfect for parents who want to wear their child’s name near their heart. *you can also ask for any word with significant meaning. *the tags can be hung on sterling silver ball chain or a base metal chain. *the average tag is approx. 1-2 inches long and a few of them on a chain have a wonderful weight in your hands. what is silver pmc? precious metal clay (pmc) is a compound made of ground silver held together with a binder in a clay form. after the design is created the jewelry is fired in a kiln and then burnished. the final product is .999 silver, a higher concentration then sterling.