Pulp-fiction authors created some of the most enduring characters of any literary genre including Tarzan, detective Sam Spade, and the sword-wielding Zorro.

The magazines that illustrated their exploits, unfortunately, haven’t fared as well. In fact, they never were built to last – the pulps were printed on cheap, wood-pulp paper (hence the name “pulp fiction),” which quickly became brittle and acidic.

Technicians in the Preservation Directorate, however, are working to give new life to the lustrous, eye-catching covers in the Library of Congress’s sprawling collection of pulp-fiction magazines. The Serial and Government Publications Division holds roughly 14,000 issues from more than 300 titles published in the United States between the 1920s and 1950s....