On that last night, Mr. Schlesinger became one of the “stars” of “Farewell, Etaoin Shrdlu,” a 29-minute documentary film with a title that Linotype operators would instantly recognize. It captured workers putting together the last papers made with the Linotype machine, the issue of July 2, 1978. Mr. Schlesinger also narrated the film, which was directed by David Loeb Weiss, a retired Times proofreader.

Invented by Ottmar Mergenthaler, a watchmaker who emigrated from Germany, the Linotype machine revolutionized publishing. It allowed for an entire “line of type” to be created at once, instead of requiring someone to piece words together metal letter by metal letter. For newspapers, the type, printed backward, was arranged in metal page forms that were used to make 40-pound page plates, called stereotypes, from which the paper was printed.

“Farewell, Etaoin Shrdlu” takes its name from the unusual key alignment on the Linotype. Striking the first 12 keys, which were in two columns at the left of the keyboard, “spelled” etaoin shrdlu. If a line of type contained mistakes, a composing room worker would strike those first 12 keys to indicate that the line should be discarded. Sometimes, “etaoin shrdlu” was overlooked and made its way into the paper. Times archives online show dozens of appearances, some more awkward than others.

In 1974, “etaoin shrdlu” appeared in the first paragraph of a story, ostensibly as a quotation from a letter by Irving Anker, then the chancellor of New York City schools, about discrepancies in the results of standardized reading tests. After computers took over typesetting, “etaoin shrdlu” appeared in print only as a reference to the technological imperfections of the past — and to the film.

Mr. Schlesinger became an expert on the Linotype as well as on Mergenthaler. He oversaw the reissuing of a privately published autobiography the inventor wrote as he neared death from tuberculosis in 1898. For a special edition, Mr. Schlesinger had the publisher, Oak Knoll Press, include a folded reproduction of a page from The New York Tribune that reflected the first use of the Linotype.