Fans of comic books will go to great lengths to keep their collections in top condition—storing comics in clear plastic or vinyl bags, buying an additional copy of an issue (reading one and leaving the other untouched), even sending away comics to be sealed in hard plastic shells. Yet, as Chloe Houseman, an intern in the Weissman Preservation Center’s paper conservation lab, recently explained at a presentation on the preservation of comics, most single-issue comic books were not made to last.

“The evolution of comic books into a collectible phenomenon has been a challenge,”...