By Alexandra Alter

New York Times

Paper is back

After years of seemingly unstoppable growth, e-book sales have started to slip, while paper has improbably bounced back. Digital book sales fell nearly 10 percent in 2015 from the previous year. Paperback sales grew by a healthy 16 percent, according to the Association of American Publishers, which tracks sales from more than 1,200 publishers.

Gray digital

Those who came of age with digital technology seem, surprisingly, to prefer paper to pixels. Young readers are less drawn to e-books. Only 13 percent of 18- to 24-year-olds primarily read e-books these days, compared with nearly 30 percent of 55- to 64-year-olds, according to a recent survey of 4,992 book buyers conducted by the Codex Group, a publishing consultancy.

Read it on the phone

Last year 15 percent of e-book buyers read their books primarily on smartphones, up from 6 percent in 2013, according to a survey of 6,000 people by Nielsen Books &Consumers. In that same period, Amazon’s dedicated e-reader, Kindle, seems to have fallen in popularity: 21 percent of e-book buyers said they read on Kindle e-readers in 2015, compared with 30 percent in 2013.

Download and listen

Sales of downloadable audiobooks have surged in recent years, vastly outpacing any other publishing format. Digital audiobook sales were up nearly 40 percent in 2015 over the previous year, according to the Association of American Publishers.

The ‘Hunger Games’ factor

The steepest drop in e-book sales was concentrated in children’s and young-adult books, where digital sales fell by 43 percent last year, probably because there wasn’t a blockbuster crossover young-adult novel series like “The Hunger Games,” which attracted millions of adult readers.

Coloring books

Coloring books! The huge coloring book surge continues as millions of adults pick up crayons to unwind. Some 12 million coloring books were sold in the United States last year, up from 1 million in 2014, and more than 2,000 coloring book titles were published, compared with just 300 the previous year, according to Nielsen. There are coloring books for every imaginable interest group, including “Game of Thrones” and “Harry Potter” ones, Hillary Clinton and Donald Trump versions, and, in a new and surprisingly durable trend, “sweary” coloring books. Because how better to demonstrate that your coloring book is not for kids than by incorporating lots of four-letter words?

Two titles in the coloring book category that are expected to be big this summer: Kerby Rosanes’ “Imagimorphia,” out this month, and Johanna Basford’s intricately patterned “Magical Jungle,” out in August.