The Evolution of Metal Clay Design

In 1996, Rio Grande in Albuquerque, New Mexico, introduced artists and jewelers in the United States to Precious Metal Clay (PMC) from Mitsubishi Materials Corp. in Tokyo. The material, a mixture of fine-grained metal powder with an organic binder, could be worked like clay, but became a solid piece of metal when kiln-fired.

Curious, the editors of AJM obtained a sample and sent it to goldsmith and writer Gary Dawson of Goldworks in Eugene, Oregon, for a little first-hand testing. "PMC is a new and interesting material that will allow the industry to rethink how we use metal in jewelry manufacturing," Dawson concluded. "It may feel clumsy to us at first, but like the tools I had to grow into early in my career, it may eventually become an important part of our manufacturing process."

Polymer clay, fine and sterling silver necklace by Judy Kuskin.

Six years later, metal clay hasn't sparked a revolution yet. (The material is now referred to simply as "metal clay" because there are two competing varieties: PMC from Mitsubishi, and Art Clay from Aida Chemical Industries in Tokyo.) But it no longer belongs to the fringes of the jewelry world, either. Growing numbers of artists are discovering the material, and they are using it in innovative and increasingly sophisticated ways.

"I see [metal clay] used in so many ways, with so many different media," says Jackie Truty, president of Art Clay World in Oak Lawn, Illinois, the U.S. distributor of Art Clay. "It's not just pure silver being used to make jewelry. It's pure silver being used with glass and fusing it together, it's pure silver being used on porcelain… The medium is just so versatile, I see it becoming integrated [in many different art mediums], and in circumstances where traditional silversmithing just can't go."

Fortunately, the ease of working with the material makes it a feasible option for many jewelers and artists. "A big advantage of PMC is that because the learning curve is rather short, it makes a viable 'second media' for a lot of people," says Tim McCreight of Portland, Maine, author of The Complete Metalsmith and an early promoter of PMC. "For me, a classic example is enameling. A lot of enamelists have devoted 15 or 20 years of learning to enamel, then they get to the point where they want to make their own metal objects, but they don't want to spend another 15 or 20 years learning the trade of goldsmith. [As a result], most of the time, you find metalsmiths who do a little enameling, or enamelists who do a little metalsmithing. With PMC, the door swings wider, and the threshold gets lower."

Unsurprisingly, some of the first designers to embrace metal clay have been polymer clay artists. "One of the challenges for polymer clay artists is to educate the public as to the value of our artwork. People say, 'Oh, it's just plastic,'" says Diane J. Mayer of Antioch, Illinois, president of the International Society of Metal Clay Artisans and a mixed media artist working in metal clay, polymer clay, and glass. "It's much easier in metal clay, because it's silver, and people automatically ascribe value to silver and gold."

Clay artists also may have been less intimidated by the material at the outset. "People who work with polymer clay really almost have a leg up, because they understand clay materials," says Barbara Becker Simon of Cape Coral, Florida, a jeweler for more than 30 years who has begun creating glass and metal clay pieces. "Jewelers trained traditionally [may be] a little bit at sea with PMC because they are used to taking a saw or a file to this very hard material, or taking a hunk of metal and smacking away and forging it. [Metal clay] doesn't behave that way."

Because the material is so unfamiliar to metalsmiths, much of the very early work seen in trade magazines and seminars had a tendency to be a little raw and unsophisticated. "For someone used to taking hours of labor to do the simplest things, [metal clay] was like, 'wow, I can press my thumb into it and I'm done,'" says jewelry designer Jennifer Bowie of Salem, Massachusetts, a certified PMC instructor.

"In the beginning, people [just] rolled out a circle, put some texture on it, and put a hole in it," agrees Celie Fago of Bethel, Vermont, a polymer and metal clay artist and instructor. "Those of us who come from a background of polymer clay saw another soft claylike material we could texture readily."

PMC, glass, and sterling necklace by Barbara Becker Simon; Photo by L. Sanders.

As with any new material or technique, however, as more people began experimenting and bringing their unique backgrounds and sensibilities to it, the work being done blossomed in new and sometimes unexpected ways. "In the last year, I've sensed in the [metal clay] community a need to go beyond, 'let's just texture it,' and now I'm seeing more untextured PMC, more three-dimensional forms, and more sophisticated and complex forms," says Fago.

In creating her polymer clay and metal clay jewelry, Fago not only shapes the clay during its malleable state, but also carves the material after it dries out. "I was delighted to find there's a great second stage: You can work it fresh or you can work it when it dries and it's leather hard," she explains. "When you take it out of the package and try to make something, it begins to dry out immediately. At the beginning, I experienced that as a bullying by the material-it wanted me to think faster. So the discovery that there was this great second stage [was very freeing]."

Even those who don't have a background in clay materials found it hard to resist experimenting with metal clay. Despite initial reluctance, Deborah E. Love Jemmott, a jeweler in San Marcos, California, became excited about the material when she began meeting with a group of jewelers who were exploring metal clay. "I resisted the material the way it was presented: I've been a jeweler for 25 years, and it just looked like a cutesy thing." But seeing what others were doing with metal clay changed her mind. For example, another member's presentation about how she molded a button in metal clay inspired Jemmott to try molding a piece of armadillo skin she'd saved for 20 years. That and other textures soon found their way into her jewelry designs, although she continues to use traditional jewelry techniques for much of her work.

Jemmott's initial reaction to the material wasn't uncommon. At first, many metalsmiths were also put off by the way metal clay shrinks: The original PMC formulation shrinks approximately 30 percent during firing. Today, however, many artists opt for new formulations that offer shrinkage rates around 10 percent. They've also learned to integrate the shrinkage into their designs.

"I love the shrinkage," says Simon. "When you put a texture into standard PMC, and it shrinks [about] 35 percent, the detail gets better."

Nor does Simon mind the fact that traditional buffing wheels can't be used on metal clay. "After being fired, [metal clay] is a little more porous than sheet fine silver, and that porosity tends to absorb the greasy compounds [used on buffing wheels]," she says. "So [metal clay artists] use other techniques. Tumblers with stainless steel shot do a fabulous job-you'll knock your eyes out with the shine you get that way. And brass brushes, whether used manually or on a mechanical buffing machine, create a very soft, lovely surface."

Shahasp Valentine, a San Francisco-based jewelry artist who has designed two lines in PMC, likes the individuality that she achieves by finishing each piece by hand. "I do all my finishing by hand with brushes and burnishers," she says, noting that she makes some of her own burnishing tools. "That gives each piece a unique texture you don't find with standard techniques. When you cast and buff, it's so perfect and mechanical. With PMC, it's the irregularities that [give my pieces] their unique qualities."

Valentine also fires ruby, sapphire, and other non-heat sensitive stones in place. "I put the stones in the wet clay [with] the findings, and it all comes out cohesive, which is important to me," she says. "If I treat it with traditional jewelry techniques after it's fired, it doesn't feel right to me."

Other artists have found metal clay's greatest asset to be the ways it can be combined with traditional jewelry techniques, such as casting. Bowie, for example, uses metal clay to create models for pieces that will be produced through traditional lost wax casting methods. "I can sit with an ounce of clay and turn out 30 little design models," she says. "[For example], I have a spring line coming out [that I designed using] 2 oz. of clay. I made 40 or 50 pieces, and picked 12 that I'm going to put into production."

Bowie also uses matrix dies to impart texture to the PMC. "If I get a die I like, I can press it in the PMC and then cut that piece apart, and suddenly I'm working on an entire design line," she says. "If I had to go and photo etch each and every piece, it'd be an awful lot of labor up front."

Eventually, large-scale jewelry manufacturers are going to discover the same advantages, says McCreight. "I'm waiting for somebody to find us and say, 'I've decided I want to start a jewelry manufacturing company, but I have no investment and little expertise, and I wanted to get started from ground zero," he explains. "You could run [a manufacturing company based on PMC] in an office building downtown with no pollution controls, no special fire needs, no gas lines to install."

And although PMC is initially more expensive than traditional silver sheet and casting grain, the time saved in production could make such an endeavor profitable. "I've done some trials on this, and they've consistently shown that the higher cost is offset by faster time and lower expenses elsewhere," says McCreight. "You need fewer tools, and the time savings is just incredible. If you carve a piece in wax, it will take an hour [to carve], then you attach a sprue, put it on a base, invest, dry, burnout, cast, [and] trim off sprues [before you reach] the finishing stages. In PMC, you can carve a little faster-maybe 40 minutes instead of an hour-and then you fire for 10 minutes and go to the sandpaper."

Whether metal clay ever becomes a jewelry manufacturing method of choice or not, what is certain is that the material's evolution is far from finished. "The people who have been working [with metal clay] the longest have been doing it five years. That's very little time," says McCreight, adding that it takes up to six months before current work makes its way into the public eye. "The best work being done today we're not even seeing [yet]."

The Right Stuff

Since its U.S. debut in 1996, Precious Metal Clay (PMC) has acquired several siblings-PMC+ and PMC3-and a competitor: Art Clay. Each of these is available in both fine silver and gold (22k for Art Clay, 24k for PMC).

In response to concerns about the approximate 30 percent shrinkage of original PMC, Mitsubishi developed PMC+, which shrinks just 10 to 15 percent. This year, the company introduced PMC3, which fires at just 1,100 F/593 C to 1,290 F/699 C -compared to approximately 1,600 F/871 C to 1,650 F/899 C for other silver metal clays-allowing sterling silver and glass findings to be fired in place. It also offers a greater tensile strength than original PMC and shrinkage rates of 8 to 10 percent.

Art Clay is also available in several forms. In addition to the standard clay form, it is sold in a "Slow Dry" formulation, which dries five times more slower than original Art Clay for a longer working time; in sheet form, for use in origami and other folding techniques; and as a paste-filled syringe, for the creation of detailed surface decorations, such as beadwork, faux granulation, and filigree. An oil-based paste is also available for making repairs and adding findings to pieces after the initial firing.

All clay varieties can be hallmarked by their metal content-for example, 0.999 silver for the silver clay-since only the precious metal is left after firing. "People write to me and [ask] how do you hallmark this work? As PMC?" says McCreight. "My answer is no. It's fine silver."

Metal Clay Resources

There are a variety of educational resources available for users of both types of clay.

1. For instruction in PMC, the PMC Guild Web site, pmcguild.com, offers a searchable database of classes throughout the United States. The Web site also includes information about the guild's PMC Conference. Contact: PMC Guild, 417 W. Mountain Ave., Fort Collins, CO 80521.
2. A calendar of Art Clay classes, including "crossover" classes for those already experienced with PMC, can be found on the Art Clay World Web site, Artclayworld.com, or by contacting Art Clay World at P.O. Box 607, Oak Lawn, IL 60454 ; 1-866-381-0100 or 1-708-857-8800.
3. The International Society of Metal Clay Artisans. For more information, visit the group's Web site at Ismca.org, or write them at P.O. Box 253, Antioch, IL 60002.