In jewelry manufacturing today, there are two important words that go hand-in-hand: speed and quality. The faster a product can be made, the sooner it’s on the shelf. But if it’s not a truly quality product, once it gets to the shelf, that’s where it’s going to stay. So the ideal is to make a top-notch product quickly. And that’s where lasers come in. Offering speed and precision, lasers can help to ensure quality with a level of repeatability that simply can’t be matched by hand. One area where that’s proving especially important is engraving.

But don’t think that engraving is limited to design work or “John loves Mary”-style messages on the insides of rings. Today manufacturers are using laser engravers on metal and stones to create everything from hallmarks to barcodes (often smaller than the unaided eye can see) that improve a piece’s ability to be traced.

For example, picture a diamond pendant in a wire basket setting, says Tino Volpe of Tiffany & Co. in Cumberland, Rhode Island.

Without access to a laser, the manufacturer would typically hallmark the metal by attaching a tag to the pendant’s chain. “But if the chain separates from the pendant, you lose that hallmark,” he points out.  “Now you can get the engraving so small that you can put the hallmark on one of the wires. You may not be able to read it with the naked eye, but if you look at it through a loupe it’s perfectly legible, clear, and identifies the metal.”

It’s that type of capability that is rapidly turning laser engravers into must-have technology for mass manufacturers.

Consider the Options
One reason that more manufacturers are bringing laser marking and engraving into their shops is the development and improvement of diode-pumped lasers. Prior to the introduction of these machines, flash-lamp-powered lasers ruled the roost. And while those models are still viable for the job, their newer counterparts offer many advantages.

The first advantage is precision. And in lasers, that comes down to the size of the beam. Flash-lamp-powered systems typically produce a beam that is about 100 microns across, says James Gervais, president of Crafford—LaserStar Technologies in Riverside, Rhode Island, and Los Angeles. By comparison, diode-pumped lasers produce a spot just 30 microns across. “When you’re marking with a laser, what you’re doing is overlaying the dots you make.” Gervais explains. Consider a common photograph, the clarity of which is measured in dots per inch. The more dots, the sharper the image. And so it is with lasers. More dots in a given space means better quality marking—and more efficient use of limited space.

Diode lasers are also more energy efficient. In a flash lamp, the emitted white light comes out in what is called a “multi-mode beam,” which can have two or three “hot spots”—areas where the energy is concentrated most. “The beam is spread out a bit—it’s not perfectly bell-shaped,” says Joshua Gold, of Laservall USA in Pawtucket, Rhode Island. “When you try to create a laser beam with white light, about 98 percent of the light and heat you pump into the chamber is waste; the other 2 percent generates the beam.” By comparison, he explains, the diode emits the exact wavelength required to produce an Nd:YAG (neodymium:yttrium-aluminum-garnet) laser beam.

In addition, flash-lamp systems typically have to be water-cooled. A compressor runs chilled water through a cooling unit in the machine. Diode machines, on the other hand, can be cooled by internal fans because they generate less heat. “That’s a tremendous service advantage to users,” Gervais says.  “They don’t have radiators or heat exchangers or filtration systems.”

And then there’s the source of the beam, and this is perhaps where the most persuasive argument for diodes comes in. Flash lamps are relatively inexpensive—in the low hundreds of dollars—compared to the diodes, which start at $10,000. But a flash lamp has a life of about 700 hours. That’s four to five months. Diodes, however, last 10,000 to 15,000 hours.

For companies that are just looking into the technology, diodes may be the clear way to go. But for companies that are already using older flash-lamp lasers, making the switch to diodes may not be necessary, as  long as they're getting the job done. Volpe notes that Tiffany currently operates about six flash-lamp lasers in its various facilities, and has for several years. The company is content with the performance and applicability of these machines and it has no current plans to upgrade to diode lasers.

For some, however, changing over may just be a question of overall savings. “The cost difference on a $100,000 machine is maybe a couple thousand dollars," Volpe says. "It’s a preference. Do you want to replace flash lamps about every 700 hours…or do you want to replace a pump diode, which lasts 10,000 hours?”

Put it to Good Use
With all this high tech floating around, how is it being brought to bear on jewelry manufacturing? For the most part, mass manufacturers are using laser engravers to place hallmarks, quality stamps, and other such necessary information on jewelry items. The lasers bring a quality and clarity to these markings that simple hand stamping can’t match.

“Over time dies and stamps break down,” says Gervais. “They’re never that legible. Over the course of the day the operator doing the stamping could be hitting it hard early in the day and light by the end of the day. There’s not a consistent standard.”

Lasers, on the other hand, will reproduce a mark exactly the same countless times every day, and without the cleanup hand stamping may require. “When you [stamp], you’re moving material, lifting it onto the sides,” says Steve Schertzer, product manager for Rofin-Baasel in Boxborough, Massachusetts. “When you [use a laser] you’re vaporizing and removing the material completely. It’s a cleaner finish.”

Furthermore, if a marking needs to be changed, rather than having to create a new stamp, the operator can simply re-type it and feed it back into the system.

Beyond hallmarks, laser engravers enable designers who work with large manufacturers to give their work a certain distinction. “A lot of designers feel that trademarking is a necessity but it takes away from the design of the piece,” Volpe says. “You don’t want it overshadowing the design.” However, he adds, since laser marking is so crisp it doesn’t threaten to impede the look as a roll stamp or hand stamp might.

In fact, Tiffany started using laser engraving at the insistence of designer Elsa Peretti, who wanted her signature to appear inside her rings. “Before the lasers, her name was put on there in block letters,” Volpe says. “She wanted her name written because it made it more personable, more identifiable with her.” The signature is scanned into a computer and fed into the laser. A few flashes of light later, each piece is marked with a perfect, fine reproduction of Peretti's actual signature, not an engraver’s interpretation of it.

Considering that hallmarks and trademarks are more a regulatory matter than an aesthetic function, why does their clarity really matter? If hand-stamped hallmarks have been acceptable in the past, why invest this kind of money in the laser? It’s all about edge, says Gold.

“These are the things manufacturers are doing to make sure they’re not giving their competitors any edge,” says Gold. “Whether [that edge] is real or not, they don’t want to take the chance.” It’s a ripple effect: As more manufacturers use the technology to improve their hallmarking, others have to follow suit or be seen as lagging behind in quality.

Get on the Fast Track
The immediacy of laser engraving can also help increase output. A laser marking system outfitted with an indexing program can engrave a pallet of 40 rings in about 10 minutes with the push of a button. That kind of output can allow the manufacturer to do custom work in large numbers on the fly.

In fact, one of LaserStar’s customers does exactly that. They make their stock items and shelve them; then, when a client calls wanting a certain model with specific markings—a hallmark and their own logo, for example—the company can pull the finished rings and complete the job. “Typically if they took an order for even 50 rings, they’d have to start from scratch,” Gervais says. “They’d have to manufacture to the order specs and that might create a two-week lead time. Now they can pull [the rings] off the shelf, bring up a file in the marker, bang out the pieces with the engraving, and turn the order in 24 hours. All the stones can be [pre]-set, all the finished hand work can be completed. They’re just making the final personalization of the piece for shipping.”

Making the tracking of a jewelry item easier is another function of laser marking. Perhaps nowhere is this more important than in the gemstone arena. For several years diamond and gemstone companies have been engraving GIA and EGL certificate numbers onto the girdles of stones for tracking purposes. With higher-end lasers, however, they can now do even more.

“Certification numbers can be used as stock-keeping units,” explains David Benderly, president of PhotoScribe in New York City. “But manufacturers can also inscribe a two-dimensional barcode with whatever information they want encoded—date, carat weight, origin, lot number, price point. Only they need to know what it means.”