A J-card is the paper card inserted in the plastic storage case of most audio cassette releases, as well as being latterly wrapped around the outside of many Blu-ray and DVD steelbooks and similar special editions. The J-card usually contains an image of the album cover, a track listing, credits, and copyright information. Most J-cards contain the title of the content on the edge for quick reference while in storage.
The J-card gets its name from being folded into the shape of the letter J (when viewed from the side) to fit inside the cassette's case.
Today, custom made CD-R covers are often called J-cards. Similarly styled covers were used in CD covers in the 1990s for single cases and are still used today.