Peter Mendelsund often says that “dead authors get the best book jackets.”

Mendelsund, who has designed striking covers for departed giants like Kafka, Dostoyevsky, Tolstoy and Joyce, dreads working with writers who demand a particular font, color, image or theme. “It ends up looking like hell,” he said.

Then last year, Mendelsund, the associate art director at Alfred A. Knopf, became his own worst nightmare. He started writing a book himself. Coming up with a cover for his book, “What We See When We Read,” a playful, illustrated treatise on how words give rise to mental images, was excruciating. As the author, he felt as if no single image could serve. As the designer, he had to put something on the front, or resign in disgrace.

His first attempt was stark and off-putting: a plain black cover with small white text. “It was like stage fright,” he said. “I just seized up.”

Stage fright isn’t a chronic affliction for Mendelsund, a 46-year-old “recovering classical pianist” who taught himself graphic design. More often, he suffers from a surfeit of ideas. In the past decade, Mendelsund has designed about 600 book jackets, ranging from a sober, sophisticated cover for Tolstoy’s “War and Peace” to his whimsical Pop Art-like treatment of Kafka’s novella “Metamorphosis,” to the hypnotic fluorescent swirls on Stieg Larsson’s thriller “The Girl With the Dragon Tattoo.”

Mendelsund has long been regarded as one of the top book designers at work today, taking his place alongside design luminaries like Chip Kidd, Alvin Lustig and George Salter. Now, he’s making his debut as a writer, with two books coming out next week. Both explore the peculiar challenges of transforming words into images, and blend illustrations with philosophy, literary criticism and design theory.

In “What We See When We Read,” which is being published by Vintage Books next Tuesday, Mendelsund tackles the mysterious way text yields vivid mental pictures, even when the author supplies very little visual detail. Most readers, for instance, feel as if they can perfectly describe Anna Karenina, even though Tolstoy gives us little more than gray eyes, thick lashes and curly brown hair. In short, illustrated chapters, Mendelsund argues that reading is an act of co-creation, and that our impressions of characters and places owe as much to our own memory and experience as to the descriptive powers of authors.

On the same day, PowerHouse Books is releasing “Cover,” a 267-page coffee-table book with more than 300 of Mendelsund’s most arresting book jackets, and dozens of rejected drafts. The images are interspersed with notes on his process, along with essays by authors of some of the featured books, including the best-selling Norwegian crime writer Jo Nesbo and James Gleick, author of the nonfiction books “Chaos” and “The Information.”

“Most designers look for a central image to sum up a book, but Peter isn’t looking for an image, he’s looking for an idea,” Gleick said in an interview. For the hardcover edition of “The Information,” Mendelsund repeated the title about 60 times, so that it looks like a flood of code.

To come up with a cover, Mendelsund begins by scribbling notes on a manuscript and underlining key thematic sentences. He hangs the marked-up pages above his computer. Then he begins cataloging his ideas on a piece of paper covered with 16 rectangles, filling each one with a word, phrase or tiny sketch. He picks the most promising concept and creates a draft on the computer.

Once he has a rough design in place, he will often switch to illustrating by hand, drawing with an ink brush, layering on paper collage or filling in blocky shapes with gouache, a dense watercolor. Finally, he prints out a mock cover, wraps it around a hardcover and leaves it on his bookshelf for a few days. If his eye is spontaneously drawn to it a day or two later, he considers his direction on the right track. If the cover disappears into the background, he knows something is missing.

He often repeats this process dozens of times. For a new edition of Julio Cortázar’s 1963 novel, “Hopscotch,” he created 60 covers before choosing one with a pattern of blue footprints imposed on white squares. “The Girl With the Dragon Tattoo” was even tougher, taking nearly 70 attempts. The resulting cover became ubiquitous as the novel went on to sell about 10 million copies.

Sonny Mehta, the chairman and editor in chief of the Knopf Doubleday Publishing Group, said the surprisingly cheerful cover probably helped make the novel a blockbuster. “I didn’t want a gloomy Nordic landscape,” he said. “It was unconventional, and it worked.”