It was a blind ad in a newspaper that caught Tony Mendez’s eye in 1965. The ad (“Artists to Work Overseas — U.S. Navy Civilians”) did not identify the employer, but it carried the whiff of adventure.

At the time, Mr. Mendez was working for Martin Marietta (now Lockheed Martin) in Denver, making technical drawings of the wiring harnesses for missiles. It was not the most exciting task.

The employer behind the ad turned out to be the Central Intelligence Agency. And Mr. Mendez’s artistic skills, which included hand-eye coordination that enabled him to look at something and copy it precisely, suited the agency’s need for a counterfeiter and forger.

And so began a career that in time would lead Mr. Mendez, who died on Saturday at 78, to orchestrate one of the most audacious covert operations in C.I.A. history: the rescue of six American diplomats from a tumultuous Iran after Islamic militants had stormed the United States Embassy in Tehran on Nov. 4, 1979. The militants held 52 Americans hostage for 444 days, a humiliating foreign policy debacle that would severely undermine Jimmy Carter’s presidency.