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Mint engravers embrace 21st century technology

It’s the stuff movies are made of. Really. The same technology that brought “Shrek” to life gives design detail to U.S. coins.

This article was originally printed in the latest issue of Numismatic News.
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It’s the stuff movies are made of. Really.


The same technology that brought “Shrek” to life gives design detail to U.S. coins.

Forget paper and pencil, plaster and clay. Today’s artist/sculptor/engraver at the United States Mint in Philadelphia works with sophisticated (and expensive) computer software to create coins and medals.

Chief Engraver John Mercanti has seen and done it all. From the days of mixing plaster to create molds to sculpting with a computer, Mercanti has been a part of the design evolution, and a strong advocate of new technology.

“In the old days, we would model the image and then I would actually make lines where the type was going to go, and I would go into a negative plaster and cut lettering by hand,” Mercanti said. “It could take longer to do the lettering than the artwork.”

In fact, the accounting department once asked how long it took the engravers to make a letter.

“We said 15 minutes,” Mercanti said.

And remember, there are lots of letters on U.S. coins.

“We’re mandated by Congress to have certain text elements on that coin,” Mercanti said. “It’s always been an exercise in design to model around that. ‘Liberty’ is the primary, but all coins have ‘Liberty,’ ‘In God We Trust,’ the date, mintmark, ‘United States of America’ and ‘E Pluribus Unum.’”

Today, they get a basin that has the lettering already on it, where it is supposed to be, said Steve Antonocci of Tanget Technologies. A private contractor, he was brought in about six years ago and tasked to bring the digital world to the Mint. Today, it’s mission accomplished.

“We’re at the forefront of this technology,” Mercanti said. “No other mint has this technology.”

And it’s a good thing they do, Antonocci said, because with the increased number of designs that come into the department every year, there is no way they could have kept up.

“We used to hand punch the mintmark on every single die,” said Mercanti. “The Mint shop would bring 200 to 300 dies in and before we did any of the day’s work, we had to take a punch and hammer and make the mintmark.”

It was not a precise science.

“We called them walking mintmarks because they’d be all over the place,” Mercanti said. Although there was a specific area the mintmark was meant to be placed, because it was done by hand, no two dies were identical.

“The hardest denomination was the nickel, because (the mintmark) was out in space,” Mercanti said.

But all that has changed with computer technology.

“It would take up to three to five days to get one satisfactory die,” Mercanti said. “Now we have a good die on the first try 99 percent of the time.”

But with new technology comes new challenges.

On an easel in the corner of the third-floor conference room at the Philadelphia Mint, are the following words:

“What’s causing cracking?”
“Heat treat?”

The engravers had met earlier with the production staff to determine why cracking was occurring on some coins.

It looked like technology got just a little too good.

Janvier machines generated soft curves, Mercanti said. With computerized sculpting, distinctive lines can be made, and those hard edges may result in stress marks that cause cracking, he said.

The answer? Go in and soften the lines created on the computer.

“Sharp corners cause stress marks and under high stress, dies crack,” Mercanti said. “So what we have to do now is go back to the data and insert round corners and soften edges.

“If we don’t, we have die cracking, and that’s unacceptable because we are judged on die life.”

The engravers have gotten so good at digital design, Mercanti said, he challenged anyone to look at the Bicentennial pennies and determine which were designed on a computer and which were designed by hand.

Technology aside, how hard is it to design a coin?

“Sometimes the design just flows; sometimes it’s a struggle,” Mercanti said.

Michael Gaudioso, who is submitting designs for the NASA commemorative coin, said they are a struggle, while the design for the Hawaii state quarter just flowed.

Mercanti isn’t really happy with the new Jefferson nickel design.

“So much of the design is to one side,” he said.

Then why not change it?

“It’s the design they selected,” he noted. “But it works.”

The most challenging design to date was the ultra-high-relief Saint-Gaudens $20 gold piece.

“That coin pushed the limits on everything,” said engraver Joe Menna.

There were so many different elements to consider including use of a split collar, and rim lettering, Mercanti said.

The engravers traveled to the Smithsonian Institute to view the original coin, taking close to 150 photographs from every angle.

The original model was in the Mint’s archives, so that was used to digitally create the new die.

“We took the original model and scanned it in 3-D, brought it into Virtual Reality, and made modifications,” Mercanti said.

Among the modifications were deepening the basin so the new coins could stack. There were many technical issues to deal with, but it was worth it.

“It’s a magnificent coin,” Mercanti said.


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