Metal Inlay Jewelry Perfect Fits

If you want to see sterling examples of precious metal inlay, look at your face in a mirror and open wide. Your fillings, assuming you have some, are perfect illustrations of this technique. Put as simply and broadly as possible, inlay is the permanent embedding of one material in another. Although inlay jewelry can involve combinations of gems, minerals and enamels, it is the joining of metal with metal that concerns us here. To better understand the basic principles of metal inlay, let’s go back to the common tooth filling. To fill a cavity, your dentist drills a hole in an afflicted tooth to remove its decayed portion, then plugs the hole with silver or gold in amalgam form.

The steps he follows are common to other inlay methods. Step one is to cut out a seating for the inlay in your tooth. This seating has to be shaped with its bottom bigger than its top so that the inlay material will have a recess to hold it snugly in place. Inlay master Steven Kretchmer , based in Los Angeles, calls this recess area an “undercutting.” Step two is to insert the filling material in such a way as to ensure that it stays put. In the case of a filling, your dentist simply dissolves precious metal in mercury, tamps the resulting amalgam-paste into the tooth with a spatula-like tool so that it spreads evenly, then lets the mercury dissolve and the filling harden. Sounds easy, doesn’t it? Well, just remember what your dentist has to do to make sure your bite is right after he finishes filling a tooth and you’ll begin to understand the skill and patience required for inlay. The level of job difficulty jumps exponentially once you try to embed, say, gold in platinum so that the metals are joined flush without the use of solder, screws-or any other fastener but the holding power of the host object itself. Other than using amalgams, there are two metal inlay techniques in wide use today: 1. mechanical and 2. molten.

Perhaps the best examples you will find of mechanical metal inlay are in the area of arms and armor. Centuries ago, Japanese metalsmiths perfected a technique called hon zogan, primarily to adorn swords, sword fittings and objects with intricate metal inlay designs. Variants of this technique also developed in Persia, Turkey and Europe. Today, American gunsmiths commonly inlay gun barrels and breaches with figurative bird and animal designs. All these embellishments involve essentially the same method. Using a wide choice of tools-ranging from acids and chisels to computerized lathes, lasers and milling
machines- artisans cut out designs in the host object that will hold matching-design inlay pieces. Since inserts are supposed to fit as precisely as puzzle parts, artisans take care when cutting out sections in the host object to make a concealed dovetail groove, or lip, underneath to act as a retainer. Next, workers tap in the inlay using special hammers. Once inserted, the inlay can either be ground flush with the surrounding metal or left raised for engraving purposes. It is important to note that if the insert can be seen from underneath the piece, it is not, strictly speaking, inlay.

Because inlay metal must be worked in various ways to make sure it fits properly, it is usually made of a metal softer than the ground metal. In most cases nowadays, this means using gold generally from 22k to 24k fineness for optimum malleability. Although rarely used for jewelry per se, another type of mechanical inlay, called “damascene,” is worth mentioning. Often used with small objects like lighters and cigarette cases, this method involves etching the surface of the host metal with tiny criss-crossing lines whose rough edges act as catches, or teeth, to grip a thin foil of metal laid on top, hammered into place and trimmed.

In most metal-inlay jewelry that we have seen recently, makers used hot-rather than cold-state metal techniques. ‘Reminiscent of pouring concrete into forms, this method involves pouring molten, or liquid, metal into specially cut out reservoirs in the host object. Designer Rudolf Erdel, OE Design, New York, calls this process “framing.” Kretchmer calls it “puddling.” No matter what it is called, molten-metal inlay involves using metals with two vastly different melting points-most often various golds with platinum. Since platinum has a much higher melting point than gold, it can act as a frame without being harmed by the poured-in molten metal. As with mechanical inlay, the process begins with
the cutting of an inlay receptacle, after which fluid metal is poured in, then left to cool and harden. “The trick,” says Kretchmer, “is to make sure the metal solidifies with as few gas bubbles and as little oxidation as possible. Learning to control the color contrast between the inlay and the host metal also takes a lot of experience and experimentation.”

To heighten the color contrast between different metals such as gold and platinum, most inlay pieces are left with a matte (dulled) finish. “Contrasting colors,” Kretchmer explains, “are better seen when metal is non-reflective.”

Although designers like Michael Bondanza have been making gold-in-platinum inlay jewelry for at least 20 years, this style is just coming into vogue-a beneficiary of the platinum renaissance. One of the newest and most notable converts to this style is Tiffany’s Paloma Picasso. She calls her collection of inlay jewelry “Little Secrets,” and it features her famous X and squiggle motifs embedded in platinum. “I wanted to experiment with smaller designs and a new subtle treatment for the metal surface,” Picasso says. “The success of my hammered gold proved that it could be an interesting track. I think that using gold to inlay platinum and circling the shapes with gold wire gives the metal a warmer feeling that fits my style. Diamonds always add a wonderful spark.

Modern, February, 1995

The “Moonlight” ring by Steven Kretchmer
Design Inc., Los Angeles, features a Trielle
diamond in a compression mounting of
platinum with 24k crystal gold inlay. | 800-759-9997 | (fax) 800-616-9997