Influential comic-book artist who helped create Spider-Man

Steve Ditko, a comic-book artist best known for his role in creating Spider-Man, one of the most successful superhero properties ever, was found dead on June 29 at his home in New York City, the police said on Friday. The Johnstown, Pa., native was 90.

The death was confirmed by Officer George Tsourovakas, a spokesman for the New York Police Department. No further details were immediately available.

Mr. Ditko, along with artist Jack Kirby and writer and editor Stan Lee, was a central player in the 1960s cultural phenomenon known as Marvel Comics, whose characters today are ubiquitous in films, television shows and merchandise.

Though Mr. Ditko had a hand in the early development of other signature Marvel characters — especially the sorcerer Dr. Strange — Spider-Man was his definitive character, and for many fans he was SpiderMan’s definitive interpreter.

Mr. Ditko was noted for his cinematic storytelling, his occasional flights into almost psychedelic abstraction, and the philosophical convictions that often colored his work. Scrupulously private, he had a mystique rare among industry superstars.

The initial visual conception of Spider-Man did not come from Mr. Ditko. According to Blake Bell’s book “Strange and Stranger: The World of Steve Ditko” (2008), that image came from Mr. Kirby, who penciled an origin story for the Marvel title Amazing Fantasy in 1962.

When Mr. Lee, Marvel’s editor, assigned Mr. Ditko to ink it, Mr. Ditko noticed similarities between SpiderMan and the Fly — a Kirby creation for Marvel’s competitor Harvey Comics from 1959 — and raised his concerns with Mr. Lee.

Mr. Kirby’s take was rejected, and the character’s origin was revamped to eliminate those similarities. (Out went a magic ring, among other elements.) Mr. Lee gave Mr. Ditko a synopsis to flesh out.

Mr. Ditko ran with the character. Spider-Man made his debut that year in Amazing Fantasy No. 15, and the character’s popularity led to his own title, The Amazing Spider-Man, which Mr. Ditko penciled, inked and largely plotted from 1963 to 1966.

Unlike Superman or Batman (characters from Marvel’s chief rival at the time, National Periodical Publications, which later became DC Comics), SpiderMan had humanizing flaws. He was hounded, not praised, by the press and the police. In his secret identity as Peter Parker, he was mocked by his peers. And he struggled with guilt over his uncle’s death, which he felt he could have prevented, and fretted about his aging aunt.

Mr. Ditko also helped conceive famous villains, like the Green Goblin and Dr. Octopus, and supporting characters.

Spider-Man’s fight scenes and aerial acrobatics had a spry kineticism that contrasted with the brawny physicality of Mr. Kirby’s compositions. Spider-Man, unlike the thunder god Thor and other signature Kirby characters, was not musclebound; he was a slender teenager. While Mr. Lee’s dialogue for Spider-Man could be buoyant, peppered with wisecracks, Mr. Ditko lent mood.

Spider-Man’s mask, obscuring his entire face, and his web-textured costume had a slightly morbid aspect. Spider-Man’s pensive moments — when Peter agonized over sacrifices his alter ego had demanded of him, for example — echoed the psychological struggles in Mr. Ditko’s earlier horror comics.

Stephen Ditko was born on Nov. 2, 1927, in Johnstown. His father, also Stephen, was a steel-mill carpenter; his mother, Anna, was a homemaker. His father bequeathed to his son a love of newspaper strips like Hal Foster’s “Prince Valiant,” and the young Stephen devoured Batman and Will Eisner’s noirish Sunday newspaper insert, “The Spirit.”

After graduating from high school in 1945, Mr. Ditko joined the Army and was stationed in Germany, where he drew cartoons for a service newspaper. In 1950, under the GI Bill, he attended the Cartoonist and Illustrator School (which later became the School of Visual Arts) in New York.

Mr. Ditko’s first work in print was in early 1953, in a romance comic from a minor publisher. For three months he worked in the studio of Kirby and Joe Simon, the creators of Captain America, before heading to Charlton Comics, which had its headquarters in Derby, Conn.

The introduction of the Comics Code Authority — a regulating body established by the industry in 1954 in response to Senate subcommittee hearings into the supposed influence of comics on juvenile delinquency — stifled Mr. Ditko’s Charlton output, which had largely covered horror, crime and science fiction.

In 1954, tuberculosis forced Mr. Ditko back to Pennsylvania, where he nearly died. After a year, he returned to New York, where he approached Mr. Lee, at the time a writer-editor for Atlas Comics, a precursor to Marvel.